Project: The cognitive neuroscience foundations for maintaining a healthy eating lifestyle
Synopsis: The goal of this collaborative project is to provide a picture of the determinants of overeating and obesity and to present a mind/brain perspective that promotes new eating habits that are healthy and sustainable.
Presented here is the first sketch of this project which will be developed more fully in the coming months. Contributions from experts in dieting, cognitive neuroscience, addiction science and others will be invited to comment, provide critiques, suggestions which will be posted on this website. The relevant basic and applied mind/brain science research foundations along with clinical and case study knowledge will be reviewed more completely in future drafts of this website posting.
The neuroscience of eating-log of recent activities
Follow up on the talk outlined below
Some new research and feedback from those who chose to participate in the followup of talk.
13 January, 2013: Is it really a surprise? In the Jan 8 2013 issue of Cell Metabolism Parks and colleagues report their findings that the body’s response to high-fat and high-sugar diets has a large genetic component. So here is more evidence that obesity (including Body Mass Index) is not just determined by what you eat but also your genetic heritage.
1 February 2013: Yet another non-surprise but nevertheless an important finding and point of view. Nora Volkow (Director of the National Institute on Drug Abuse) and colleagues published an article on the neurbiological basis forfood addcition and obesity (see The Addictive Dimensionality of Obesity,” Biological Psychiatry, February 2013). There is lots of speculation in this report and some data but the bottom line seems to be that “drug and food addiction allegedly share genetic, molecular, neurobiological, and behavioral mechanisms that, when coupled with environmental triggers, have “the potential to facilitate or exacerbate the establishment of uncontrolled behaviors. “
At 7:30 on December 4, 2012 I spoke on the subject of unhealthy and healthy eating styles from a neuroscience perspective. The tile of the talk was ‘Eating with a small spoon: Weight control from a neuroscience perspective’
As part of the talk audience participants could volunteer to monitor (record) their successes and failures in tracking one specific target eating behavior that could form the foundation of long term changes in their eating patterns. The broad outline of their task is summarized in the table below. I have yet to meet with them and get some sense of their experience in trying to alter how they eat, deal with triggers for eating the ‘wrong foods’, and the other many factors that contribute to out of control eating. In the meantime here is a preview of what I have learned from talking to the overweight and their struggles with weight control.
- Goal setting itself is difficult and requires some support and guidance.
- There is enormous day-to-day fluctuations in the successes (and failures) in meeting an eating style goal that has been chosen as the target behavior to be learned.
- People are surprised in what they learn about how they eat and how that may contribute to their obesity, that is when they pay attention to how they eat. The exercise of tracking the eating target they chose to work on opens up awareness to all sorts of features of how they eat.
- Weight loss seems to continue to be elusive even when subjects feel that they are successfully changing a target eating behavior (like eating more slowly). Ignoring weight loss when this is what individuals want to happen is tough to handle. If we work hard at something we want to see some success. It is really hard to convince individuals that in the long term changing how they eat (such as a target eating behavior) is what really pays off.
- Emotions such as stress overwhelm plans to control eating. This is not a surprise but it is nevertheless startling to hear about the power of emotions to obliterate the best laid plans to control eating. Not sure how to handle this problem. Will have to give it a good deal of thought and input from appropriate experts.
- We are all future discounters. That is, a candy in the hand is worth loads more than some weight loss that might occur months later. This is a human drama that is played our in many arenas.
- Success in controlling eating in the overweight brings extraordinarily powerful rewards, enhanced self-worth, pride. I have learned that individuals that have gained fame in some of their scientific discoveries and publications derive more satisfaction from successful weight loss than their scientific-professional accomplishments. I am surprised at the power of this type of accomplishment. Maybe I am naïve.
- Addictions are powerful and restrict our freedom (our choices) in making all sorts of decisions. We underestimate the extent to which a food addiction can capture our brains (our options around food). That is what I have heard from individuals talking about their own struggles with weight control. At a minimum we under appreciate what it means to be addicted and therefore how hard it is to escape from a food addiction. No doubt that avoiding cues that trigger unhealthy eating is a useful start. When the eating cues are there then not indulging seems to be impossible. Don’t bring the gallon of ice cream home.
- Most of the overweight that I have talked to are vaguely aware of the fact that they eat to fast, eat too much, have trouble stopping eating their favorite treats (until they are all gone). It is hard to eat just a few potato chips.
- Subjects report feelings of regret, disappointment, discouragement when they fail to control what they eat.
New research of interest (a news snapshot reprinted here
22 February 2013: Fighting obesity doesn’t get easier. It turns out that children with fat fathers show epigenetic changes that make them vulnerable to becoming obese. The finding is not all that surprising given what is known about the link between parental condition and the epigenetics and health (paper in Nature, 2010). Adelheid Soubry, started with what is known, that it takes 2 months for sperm to mature providing an important window of paternal influence, and then found that children with obese fathers were likely to have less methylation, or hypomethylation, on a certain region of the IGF2 gene than children whose fathers were not obese. This is one factor that can increase the liklihood of becoming obese (see Soubry et al., “Paternal obesity is associated with IGF2 hypomethylation in newborns: results from a Newborn Epigenetics Study (NEST) cohort,” BMC Medicine, 1741-7015-11-29, 2013.
Organization of this collaborative project listing
Part I: An outline of a talk to a general audience scheduled for the evening of Dec 4, 2012 (7:30), at the Goldman auditorium of the JCC of Greater Washington (Rockville MD). Posted here is a synopsis of the talk, an outline and supporting notes used for the talk. The slides that will be used to illustrate the points being made will be posted later.
Part II: Pertinent areas of mind/brain scientific and clinical (applied) research
Some of the topics to be explored include:
- Cue-dependent eating
- Characterizing the eating habits of the obese
- Neural (and behavioral) basis of (food) addiction
- Prevention of obesity based on modeling and the development of executive functions
- The cognitive neuroscience foundations of self-regulation
- Emotions (including stress) and eating (emotion-driven cognition vs. ‘cool’ cognition
- The development of eating expertise that can lead to obesity and what is required to learn new, more adaptive, expertise
- Automatic vs. controlled cognitive operations
- Analysis of the features of diets and other weight reduction interventions.
- The power of habits and the nature of unlearning and learning new skills.
Part III: Forms of dieting and weight control interventions in current practice
- Knowledge which is generally a weak vehicle for altering beliefs or how we behave
- Self-directed plans that prescribe what we should eat (types of food, how much). Generally they are used for limited periods of time. Some of prescribed diet plans also provide forms of group support
- Diet plans that are not self-directed but controlled by a provider who is contracted to provide all of the food to be consumed
- Biological treatments such as drugs, hormones, surgery
- Behavioral treatments (cognitive behavior therapy)
- Self-image manipulations
- Cognitive neuroscience perspective
Part IV: Formulating a blueprint for learning a healthy eating lifestyle
Features include:
- A cognitive analysis leading to well designed goal setting
- No diets are fun or easy. To be told that is a scam.
- A cognitive analysis that provides the details of current eating styles. This leads to uncovering automated behaviors, making them explicit, retraining eating styles (explicitly) and finally automating new eating behavior. It takes a long time to move from explicit changes in how we eat and automating what was learned
- Changing how we eat will, without a doubt, also be riddled with failures. Train to anticipate response to failure as well as rewarding success (a must)
- Designing the eating environment (including presence of cues, attentional constraints, utensils, speed of eating)
- Modeling and social support
- Prevention of obesity in kids (the role of modeling and executive function skills
Part V: Some of the details of basic and clinical research foundations (organized by topics)
- Bibliography and commentary
- Links to what we know about addiction, the nature of cognitive functions as they relate to topics such as addiction, cue-dependent priming of overeating, self-regulation and inhibition in eating behavior
Part VI: Case studies
Synopsis of the experiences of individuals who tell us about their successes and failures in dieting and maintaining weight loss.
One thing that I would tell anyone who wants to try dieting once, or those who are trying for the nth time to lose weight is to not be hard on themselves.
It is so silly, isn’t it? Why is it so surprising that we do one more irrational thing like letting our selves get fat, putting our health in jeopardy, eating a pint of ice cream knowing that we will feel awful about it a half hour from now.
We are forgiven and need a break, lots of them. We are human and do ‘stupid’ things all the time. Why should we expect to live rational sensible lives? What is the point of being rational all the time? Boring and unrealistic. Let us all wave a wand that gets us off the hook so that we don’t feel we have to consistently doo the things that are good for us, or logical, or reasonable, but instead we need to acknowledge that our brains have other things in mind for us.
Outline of talk followed by supporting details
Eating with a small spoon: Weight control from a cognitive neuroscience perspective
Synopsis of talk
For many of us gaining weight is easy while dieting to lose weight is hard and unpleasant. Maintaining weight loss is even more difficult than dieting. In this talk we review: the eating habits of the overweight; cues that trigger overeating; overeating as a form of addiction; different treatments for obesity (including varieties of diets); why, in the long run, diets generally fail. A mind/brain science perspective is used to provide a sketch of the eating styles of the obese and what it takes to change how we eat. The features of that sketch include; the nature of self-regulation (willpower); inhibition; how habits work and how one changes them; mental operations that are automatic compared to those that are part of awareness; the reward brain system; priming the reward system; learning skills as children that can be useful in preventing obesity. The overweight need to not only change what they eat but how also how they eat and that requires sustained systematic effort. It requires learning ‘new ‘cognitive skills and practicing those skills for an extended period of time.
I. Introductory remarks
The goal of my talk is to provide a roadmap of a number of important and related issues having to do with weight control. My picture of being overweight, dieting, and not gaining back the weight lost is from the perspective of cognitive neuroscience. Here are a dozen themes about becoming overweight and dieting that I will consider together and I hope you will think about them some more later.
Some questions
- How do we become overweight? Knowing how the overweight become overweight provides clues for how to lose weight and maintain weight loss.
- Why do diets succeed and fail?
- What are the eating characteristics of the overweight eater?
- What are the features of popular kinds of diets and other weight control interventions?
- What puts kids at risk for becoming obese?
- What does it mean to have a food addiction?
- What is automatic eating and why is it important?
- What are the cues for eating and stop eating in normal weight folks compared to those that are obese?
- What does will power, self-regulation, impulsivity, inhibition, have to do with healthy eating lifestyle?
- How do we unlearn our poor eating habits and learn new ones that promote a new healthy lifestyle of eating?
- What does cognitive neuroscience have to do with any and all of these issues?
Here are some things many of you already know all too well.
- It is hard to lose weight and even harder to keep weight off
- Being overweight is an important health risk and being overweight weighs heavily on your psyche.
- You have tried several diets and while you start with loads of motivation and enthusiasm positive results are harder to achieve than the promotional promise you would happen. Worse yet you raced through a diet, lost pounds and then months later the weight loss was regained often with additional dividends (pounds). You battle with your bulge continues to be discouraging
- There are no magic formulas for losing weight and maintaining weight loss.
- Knowledge is not enough …..Must change your eating habits which requires disciplined hard work, patience, time. Changing lifelong over-learned habits is hard and requires a mix of bravery, patience and self-empathy. While we should consider carefully the foods we eat we must also develop an understanding of how we eat. Cognitive neuroscience knowledge can help us on our journey to accomplish the goal of losing unwanted pounds and eating without getting fat.
There are no magic formulas for losing weight and maintaining weight loss. You can be successful in changing your eating habits but for that to happen requires disciplined hard work, patience, time, and the self confident feeling that you are on the right track. Changing lifelong over-learned habits is hard and requires a mix of bravery, patience and self-empathy. While we should consider carefully the foods we eat we must also develop an understanding of how we eat. Cognitive neuroscience knowledge can help us on our journey to accomplish the goal of losing unwanted pounds and eating without getting fat.
II. Who are the overweight and how did they get that way?
- Lots of measures of who is overweight and new ones emerge all the time.
- Being overweight and staying that way requires well-learned eating that is now virtually automatic. The overweight are experts at their eating craft. Staying fat is a powerful habit that is hard to break.
- The internal and external cues for eating and stop eating are different from those of normal weight folks.
- For many overeating is an addiction. Food for the obese is a bit like an addicting drug triggering hyper activity in the brain’s dopamine reward system. We know a great deal abut how addictions ‘work’ and why it is so hard to treat them.
- Overeating is automated in the overweight individual.
- Much of what drives maladaptive eating is outside of awareness.
- Self-regulation of eating is often compromised in overweight individuals. These same people often demonstrate that they have strong well-developed executive functions (which includes self-regulation skills).
- Self-regulation functions are often disrupted in the presence of seductive foods in the overweight.
- Emotions (such as stress) can exaggerate automatic (cue-dependent) eating while at the same time disrupting self-regulation functions.
- Learning to overeat and eat automatically often starts early in childhood. Modeling how parents eat is one strong determinant for defining the eating habits of children. It is also important to learn executive cognitive skills (such as self-regulation) since this is important in the delay of immediate gratification. Children who have acquired that skill early are much less likely to become fat.
1. Cue-dependent eating
2. Characterizing the eating habits of the obese
3. Neural (and behavioral) basis of (food) addiction
4. Prevention of obesity (modeling, executive functions)
5. Cognitive neuroscience of self-regulation
6. Emotions (including stress) and eating
7.Automatic vs. controlled eating (cognitive) operations
8. Cognitive features of diets and other weight reduction interventions
9.The power of habits (unlearning and learning new skills)
IV. Interventions:
- Knowledge: Most overweight individuals have lots of relevant knowledge about the health risks of being overweight and what are healthy foods. Turning knowledge into behavior is what is difficult to do. Habits and beliefs survive the onslaught of knowledge and therefore are hard to change.
- Types of treatments of obesity include: a) Self directed plans that guide restriction on food intake and the types of food consumed. Loads of diet plans are available. It is likely that total calories consumed is what is most likely to lead to success rather than the specifics of what is eaten. Most of the diet plans designed for the short term. b) Food intake controlled by outside source (delivering all the foods that are to be consumed); c) Biological treatments such as drugs, hormones, surgery; d) Behavioral treatments (cognitive behavior therapy); e) Self-image manipulation; f) A cognitive neuroscience approac
- Why diets are unsuccessful in maintaining weight loss?:a) They are often a dramatic shift from habitual eating habits that are therefore not sustainable; b) Since most diet are brief there is no time to unlearn poor eating habits and learn new ones; c) It takes a very long time to learn new eating habits
IV. Prevention of obesity (in children)
- Modeling and foods consumed
- Self-regulation and executive functions training
- What have we learning from cognitive neuroscience that can be translated and applied to effective weight reduction strategies that also prevent relapse? Some of the features include:
- Become aware of more than the food you are eating and more on how you eat.
- De-automate eating, bringing eating under conscious control. Learn to be aware of what you are eating, how you eating, the taste of food. The point here is to deconstruct a highly reinforced habit in order to build (learn) new habits that work in terms of weight control. Successful dieting should be measured by changes in how you eat rather than the number of pounds lost. It is learning a new skill.
- Carefully designed, realistic, goal setting. Picking small goals those that likely will lead to success. You are not competing with anyone else but instead on guided by realistic goals you set for yourself. You must appreciate how very hard it is to change a habit like unhealthy eating styles and any progress you make to reverse that should be seen as a major victory.
- Some strategies that may be helpful in de-automating poor eating habits include; use of systematic diaries, changing the dynamics of how you eat (speed of eating etc.) noting what food tastes like, paying attention to how you are eating rather than be distracted by sources such as watching television.
- Hone self-regulation skills. Self-regulations are learned (starting in early childhood) and can be enhanced with more learning (even in adults).
- Introduce more activity in daily routines not because more calories are burned but changing the habits of living into a healthier lifestyle has far-reaching effects that also impact how we eat. Change facilitates change.
- Healthy eating styles can be taught to children. This includes training of executive functions (self-regulation skills).
- You can do only a limited of ‘hard’ things at a time. Losing weight is very difficult and to interpret failures in dieting as a defect in character, weak backbone, impaired will power is neither correct nor useful. Furthermore when other important tasks require attention and sustained effort those cognitive activities make it that much harder to mobilize self-control efforts on dieting. You can do only so many hard things at the same time. Be kind to yourself.
- Maintaining motivation: Failures are part of what we face when dieting and trying to sustain weight loss. Reward success and be gentle in response to failures.
VI. Conclusions
What should we do? Some thoughts. Successful dieting should be measured by changes in how you eat rather than the number of pounds lost. It is learning a new skill.
Keep a diary…make how you eat explicit
While eating keep other activities to a minimum.
Eat slowly, (strategically and deliberately).
Be proactive.
Reward yourself well and often.
Reward yourself well and often.
………and some more details
1. Losing weight and keeping it off is difficult because it requires changing life-long automated habits that have been highly “rewarded’.
2. The laws of physics are still true. Energy exchange in the body is lawful. Consume more energy generating foods than your body burns will get you to gain weight and the opposite also holds.
2. While what you eat is important but how you eat is even more important in maintaining healthy eating style.
3. To change how we eat requires that we de-automate our current eating habits, learn new habits and practice those skills so that they, in turn, become automatic
4. Carefully designed, realistic, goal setting. Picking small goals those that likely will lead to success. You are not competing with anyone else but instead on guided by realistic goals you set for yourself. You must appreciate how very hard it is to change a habit like unhealthy eating styles and any progress you make to reverse that should be seen as a major victory.
5. Some strategies that may be helpful in de-automating poor eating habits include; use of systematic diaries, changing the dynamics of how you eat (speed of eating etc.) noting what food tastes like, paying attention to how you are eating rather than be distracted by sources such as watching television.
6. Introduce more activity in daily routines not because more calories are burned but changing the habits of living into a healthier lifestyle has far-reaching effects that also impact how we eat. Change facilitates change.
7. Healthy eating styles can be taught to children. This includes training of executive functions (self-regulation skills).
8. You can do only a limited of ‘hard’ things at a time. Losing weight is very difficult and to interpret failures in dieting as a defect in character, weak backbone, impaired will power is neither correct nor useful. Furthermore when other important tasks require attention and sustained effort those cognitive activities make it that much harder to mobilize self-control efforts on dieting. You can do only so many hard things at the same time. Be kind to yourself.
9. Maintaining motivation: Failures are part of what we face when dieting and trying to sustain weight loss. Reward success and be gentle in response to failures.
10. Try picking one aspect of how you eat and that if changed can be quite helpful. Track that aspect of eating in detail over a period of weeks noting in a log your successes and failures (see table below).
……..and now for some details (and supporting references) in support of the outline above.
Types of interventions that are used to ‘treat’ obesity
- Knowledge: Most overweight individuals have lots of relevant knowledge about what to eat and not eat. Knowledge in itself is rarely sufficient to support healthy eating. Putting knowledge into action (changing habits) requires more than knowing what to do.
- Diets: Many available and they vary based on types of foods prescribed, amount to be eaten, calorie intake, whether they are self-directed or controlled by others.
- Biological treatments: drugs, hormones, surgery
- Behavioral interventions: Behavior therapy, eating diaries, image manipulation, neuroscience perspective (a new approach).
- Diets plus exercise: Exercise as part of a healthy lifestyle and it also burns calories.
- Prevention: Methods that may be useful in preventing children from growing up overweight
Dieting
A. How should I diet? Let me count the ways
Many diets are available. What are their features? How do they work or don’t work? What matters more the form of the calories or total calories consumed?
Diets aren’t new but have been around forever. The ancient Greek/Roman historian, biographer Plutarch (46 – 120 AD) pointed out that ‘It is a hard matter, my fellow citizens, to argue with the belly, since it has no ears. More ‘recently’ William Banting published a pamphlet in 1863 entitled Letter on Corpulence, Addressed to the Public in which he describes his own low-carbohydrate, low-calorie diet that had led to his own dramatic weight loss.
Since then new diets pop up all the time and each is touted to be the best, the easiest, the most efficient, the healthiest. I would guess there are more diet books available for sale at Barnes and Noble than any other type of book.
An excellent summary of all of the popular diets and their relative merits is provided by Irene Strychar in a review article entitled Diet in the management of weight loss (Canadian Medical Association Journal CMAJ January 3, 2006 vol. 174 no. 1 56-63)
Another simple review of the various types of diets that are currently in vogue can be found by searching for the term ‘dieting’ and choosing Wikipedia, the free encyclopedia.
B. Classifying diets
1. Most diets are self-directed. That is, you are in charge of putting into action a prescribed plan to lose weight. You are also the one to monitor the success of the diet.
2. Some self-directed plans also provide support from other dieters and/or a coach. For example Weight Watchers dieters get together regularly (once a week), weigh in, talk about their successes and failures and encourage each other’s efforts
3. Some diet plans are directed from an outside source. Food that is consumed is not self prepared but delivered (controlled by the form and amount of the food to be consumed).
4. Some diets are a combination of prescribed eating plans along with medications that may, for example, suppress appetite.
5. Diets that are complex (regardless of type) are hard to follow and therefore more likely to fail.
Types of diets
The names are familiar and includes: promote their ‘unique and effective’ diets include; Atkins; Best Life Diet; Biggest Loser; Cabbage Soup; Hallelujah Diet; Jenny Craig; NutriSystem; Ornish; South Beach; 3 Day Diet; Weight Watchers; Zone; Brown Fat Revolution and we can go on and on. You can be assured that this dieting is a big business with lots of hype associated with each diet.
- Low-fat diets: Reduce the amount of calories from fat
- Low-carbohydrate diets: These are diets that are high in protein and fats and low in carbs. Atkins or South Beach are examples of these diets
- Low-calorie diets: Reduce the number of calories consumed (from any source). One example of this type of diet is Weight Watchers
- Very low-calorie diets: These are diets that are difficult to sustain since they restrict calorie intake drastically but do maintain protein intake. These are often liquid diets.
- Combinations of the above provided to you: by diet planners such as Jenny Craig
- Diet food provided plus medication and councelor: Diets with medinices such as those that activate brain serotonin such as The Serotonin-Plus Weight Loss Program which combines dietary plan, weekly visits with a counselor and a appetite suppressant.
Comparing the value of different diets
- Some individuals may benefit more from one type of diet than another. For example diabetics that are overweight are perhaps better off using a low carbohydrate diet. Measuring insulin level may be a useful piece of information in choosing a diet plan.
- The scientific evidence-based debate continues about the value of one diet strategy vs. another. Some of the references below provide a picture of the confusing details about the relative merits of one diet vs. another.
- The debate continues about whether all calories end up being the same, that is, calories equal calories equal claroirs. The balance of the evidence seems to be that it does not matter the form of the calorie intake what matters is how many calories are consumed. Consume less than you need and you will lose weight. The most recent complelling evidence for this conclusions is based on the research of Julius Hirsch at the Rockerfeller Institute (new York City).
Some references that support some of the points made above
Ashley JM, St Jeor ST, Perumean-Chaney S, Schrage J, Bovee V. Meal replacements in weight intervention. Obes Res 2001;9:312S–20S.
Bantle, JP; Wylie-Rosett, J; Albright, AL; Apovian, CM; Clark, NG; Franz, MJ; Hoogwerf, BJ et al. American Diabetes Association; (2008). “Nutrition Recommendations and Interventions for Diabetes”. Diabetes Care 31 (Suppl 1): S61–78.
Beresford SA, Johnson KC, Ritenbaugh C, et al. (2006). “Low-fat dietary pattern and risk of colorectal cancer: the Women’s Health Initiative Randomized Controlled Dietary Modification Trial”. JAMA 295 (6): 643–54.
Ditschuneit HH, Flechtner-Mors M. Value of structured meals for weight management: risk factors and long-term weight maintenance. Obes Res 2001;9(suppl 4):284S–9S.
Ditschuneit HH, Flechtner-Mors M, Johnson TD, Adler G. Metabolic and weight loss effects of a long-term dietary intervention in obese patients. Am J Clin Nutr 1999;69:198 –204.
Ebbeling CB, Leidig MM, Feldman HA, Lovesky MM, Ludwig DS (2007). “Effects of a low-glycemic load vs low-fat diet in obese young adults: a randomized trial”. JAMA 297 (19): 2092–102.
Feiden, Margo. “Margo Feiden’s The Calorie Factor,” Simon & Schuster
Foster GD, Wyatt HR, Hill JO, et al. (2003). “A randomized trial of a low-carbohydrate diet for obesity”. N. Engl. J. Med. 348 (21): 2082–90.
Garg A, Bantle JP, Henry RR, et al. (1994). “Effects of varying carbohydrate content of diet in patients with non-insulin-dependent diabetes mellitus”. JAMA 271 (18): 1421–8.
Gardner CD, Kiazand A, Alhassan S, et al. (2007). “Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial”. JAMA 297 (9): 969–77.
Halton TL, Willett WC, Liu S, et al. (2006). “Low-carbohydrate-diet score and the risk of coronary heart disease in women”. N. Engl. J. Med. 355 (19): 1991–2002.
Hannum SM, Carson L, Evans EM, et al. Use of portion-controlledentrees enhances weight loss in women. Obes Res 2004;12:538 – 46.
Howard BV, Manson JE, Stefanick ML, et al. (2006). “Low-fat dietary pattern and weight change over 7 years: the Women’s Health Initiative Dietary Modification Trial”. JAMA 295 (1): 39–49.
Howard BV, Van Horn L, Hsia J, et al. (2006). “Low-fat dietary pattern and risk of cardiovascular disease: the Women’s Health Initiative Randomized Controlled Dietary Modification Trial”. JAMA 295 (6): 655–66.
MetzJA,SternJS,Kris-EthertonP,etal.Arandomizedtrialofimproved weight loss with a prepared meal plan in overweight and obese patients.Arch Intern Med 2000;160:2150 – 8.
Nordmann AJ, Nordmann A, Briel M, et al. (2006). “Effects of low-carbohydrate vs low-fat diets on weight loss and cardiovascular risk factors: a meta-analysis of randomized controlled trials”. Arch. Intern. Med. 166 (3): 285–93.
Prentice RL, Caan B, Chlebowski RT, et al. (2006). “Low-fat dietary pattern and risk of invasive breast cancer: the Women’s Health Initiative Randomized Controlled Dietary Modification Trial”. JAMA 295 (6): 629–42.
RothackerDQ,StaniszewskiBA,EllisPK.Liquidmealreplacementvs traditional food: a potential model for women who cannot maintain eating habit change. J Am Diet Assoc 2001;101:345–7.
Strychar I (January 2006). “Diet in the management of weight loss”. CMAJ 174 (1): 56–63.
Sacks FM, Bray GA, Carey VJ, et al. (February 2009). “Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates”. N. Engl. J. Med. 360 (9): 859–73.
Samaha FF, Iqbal N, Seshadri P, et al. (2003). “A low-carbohydrate as compared with a low-fat diet in severe obesity”. N. Engl. J. Med. 348 (21): 2074–81
Stern L, Iqbal N, Seshadri P, et al. (2004). “The effects of low-carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial”. Ann. Intern. Med. 140 (10): 778–85.
Behavioral interventions
Behavior therapy has been used for many decades to treat symptoms associated with psychiatric disorders. The major feature of this approach to changing behavior is to focus on the to-be changed behavior and not on the developmental history of the meaning of symptoms or even how they got there. There are different forms of behavior therapy in use. Some focus on the cognitive components of behavior (like negative thoughts) while others target overt observable behavior (like thumb sucking). The perspective of cognitive therapy is that thoughts (or cognitions) affect feelings and then how you behave. For treating obesity behavioral therapy is designed to train individuals to develop skills that support healthy eating. In other forms of behavior therapy the notion is that it does not matter what you experience in your mind it is the behavior itself that is the target for change and then your feelings will change as a result of the behavior change.
Targets of behavior therapy include:
- Realistic goal setting (unrealistic goals often doom dieters to fail).
- Planning diets with very small changes in eating patterns
- Learning to self-monitor eating behavior
- Slowing eating
- Keeping a systematic account of what you eat.
- Combining systematic regimens of dieting and exercise
- Correct negative thoughts and feelings that occur when goals not met (a cognitive therapy goal).
- Image manipulation. Changing how someone sees themselves and perhaps acting the part of someone else as in a play.
- Targeting behaviors that are important in adhering to a diet.
- Use of diaries
- Managing food cues that stimulate out of control eating.
Behavioral treatment of obesity references
Baker RC, Kirschenbaum DS. Self-monitoring may be necessary for successful weight control. Behav Ther 1993;24:377–94.
Beck AT. Cognitive therapy and the emotional disorders. New York: International Universities Press, 1976
Beck AT, Rush A, Shaw B, Emery G. Cognitive therapy of depression. New York: Guilford Press, 1979
Brownell KD. The LEARN program for weight management 2000. Dallas: American Health Publishers Co., 2000.
Butler AC, Chapman JE, Forman EM, Beck AT. The empirical status of cognitive-behavioral therapy: a review of meta-analyses. Clin Psychol Rev 2006;26:17–31.
Cooper Z, Fairburn CG. A new cognitive behavioural approach to the treatment of obesity. Behav Res Ther 2001;39:449–511.
Cooper Z, Fairburn CF, Hawker DM. Cognitive-behavioral treatment of obesity. A clinician’s guide. New York, NY: Guilford Press, 2003
Foster GD, Wadden TA, Phelan S, Sarwer DB, Sanderson RS. Obese patients’ perceptions of treatment outcomes and the factors that influence them. Arch Intern Med 2000;161:2133–9.
Foster GD. Goals and strategies to improve behavior-change effective- ness. In: Bessesen DH, Kushner RF, eds. Evaluation and management of obesity. Philadelphia: Hanley & Belfus, 2002;29 –32.
Foster GD, Makris A. Behavioral treatment, Part B, Practical applications. In: Foster GD, Nonas CA, eds. Managing obesity: a clinical guide. Chicago: American Dietetic Association, 2004;76 –90.
Foster GD, Makris A. Behavioral treatment, Part B, Practical applications. In: Foster GD, Nonas CA, eds. Managing obesity: a clinical guide. Chicago: American Dietetic Association, 2004;76 –90.
Foster GD, Wadden TA, Vogt RA, Brewer G. What is a reasonable weight loss? Patients’ expectations and evaluations of obesity treatment outcomes. J Consult Clin Psychol 1997;65:79 – 85
Jeffery RW, Wing RR, Thorson C, Burton LR. Strengthening behavioral interventions for weight loss: a randomized trial of food provision and monetary incentives. J Consult Clin Psychol 1993;6:1038 – 45.
Jeffery R W, Wing R R ,Thorson C, Burton L R. Use of personal trainers and financial incentive to increase exercise in a behavioral weight-loss program. J Consult Clin Psych 1998;66:777– 83.
Jeffrey RW, Wing RR, Sherwood NE, Tate DF. Physical activity and weight loss: does prescribing higher physical activity goals improve outcome? Am J Clin Nutr 2003;78:684 –9.
Jeffery RW, Wing RR, Mayer RR. Are smaller weight losses or more achievable weight loss goals better in the long term for obese patients? J Consult Clin Psychol 1998;66:641–5.
Mann T, Tomiyama J, Westling E, Lew A, Samuels B, Chatman J. Medi- care’s search for effective obesity treatments: diets are not the answer. Am Psychol 2007;62:220 –33.
Ramirez EM, Rosen JC. A comparison of weight control and weight control plus body image therapy for obese men and women. J Consult Clin Psychol 2001;69:440 – 6.
Stahre et al., “A short-term cognitive group treatment program gives substantial weight reduction up to 18 months from the end of treatment. A randomized controlled trial.” Eating and Weight Disorders. Vol. 10. p 51-58 (2005)
Stuart RB. Behavioral control of overeating. Behav Ther 1967;5: 357– 65.)
Stuart RB. Behavioral control of overeating. Behav Ther 1967;5: 357– 65.
weight control. In: Wadden TA, Stunkard AJ, eds. Handbook of obesity treatment. New York: Guilford Press, 2002; 301–16.
Stunkard AJ. Talking with Patients. In: Stunkard AJ, Wadden TA, eds. Obesity: theory and therapy, 2nd ed. New York: Raven Press, 1993;355– 63.
Tsiros et. al. Cognitive behavioral therapy improves diet and body composition in overweight and obese adolescents1–3 Am J Clin Nutr 2008;87:1134–40
Wadden TA, Stunkard AJ, eds. Handbook of obesity treatment. New York: Guil- ford Press, 2002;42–72.)
Wadden TA, Foster GD. Behavioral treatment of obesity. Med Clin North Am 2000;84:441– 61.
Wansink, B. Mindless Eating: Why We Eat More Than We Think, New York: Bantam Dell (2006).
Wing RR. Behavioral weight control. In: Wadden TA, Stunkard AJ, eds. Handbook of obesity treatment. New York: Guilford Press, 2002; 301–16.
Prevention of obesity
The number of obese children is growing by leaps and bounds. These children eat the ‘wrong’ foods, eat too much and do not get much exercise. They gain weight become overweight adolescents and then continue their trajectory of unhealthy eating into their adult years. What to do to break this cycle of an unhealthy lifestyle? We know, you know, that children model their parents so the obvious, overweight parents put their children at risk for becoming obese. Healthy eating is learned first at home and then at school and with friends. The point is that healthy and unhealthy eating styles are learned.
In a culture in which instant gratification is the norm (not just for children but also many adults) avoiding too many foods with loads of sugar or fatty salty foods becomes a real problem. After all we are ‘wired’ to like sweet and fatty foods and if we were living in a world where food availability was not a given then banking high calorie foods would make sense. We are no longer hunter0gatherers and therefore our taste in food is no longer as adaptive as it was 5000 years ago. We humans are not alone in having a sweet and fat tooth.
In a study published in Nature Neuroscience on March 28, 2010 (authored by Paul Kenny of the Scripts Research Institute) we learn that rats, just like the rest of us, are delighted to stuff themselves with fatty treats such as bacon, sausage chocolate (light and dark) and even cheesecake. It is also not a surprise to learn that just like sex, drugs, and winning a prize in an essay writing contest triggers the release of the neurotransmitter dopamine, which is the neurochemical that is the lead player in our reward system. No wonder kids (and adults) have trouble eating properly. More about the role of the brain’s reward system in regulating eating behavior is detailed below in the section labeled ‘A Neuroscience perspective on being overweight, losing weight and developing a healthy eating lifestyle’.
Preventing obesity must be considered in the context of the development of brain function and specifically the development (learning) of cognitive skills such as self-regulation, which includes leaning to plan, monitor what we are doing, evaluate what we are doing, and learning to inhibit our impulses. I suppose you would say that is a major feature of growing up into a responsible adult. Children are toilet trained and also, eventually no longer need instant gratification. In fact when it comes to food (and in other arenas) we know that many adults, just like children, need to be instantly gratified. The important point is that executive functions such as self-control are learned just like so many other skills.
Forty years ago the Stanford University psychologist Walter Mischel conducted a simple experiment using 5 year olds as subjects. He had kids come into the laboratory and gave them an option of getting 2 marshmallows immediately but if they waited a short while they could get many more goodies. About ¾ of the kids couldn’t wait but went for the soft balls of pleasure immediately and ¼ of them said they would wait for many more marshmallows to come. Mischel tracked these kids over time and right up to today. The kids were now adults. The differences (on average) between the kids who could wait for more marshmallows compared those kids who couldn’t wait, who couldn’t suppress their need for instant gratification were startling. The kids with the self-control ended up with higher SAT scores when applying to college, were much more successful, had fewer psychiatric problems and yes, you guessed right, they were far less likely to be overweight. It also turns out that, based on an ongoing study of many of these same kids now grown up that the way their brains functioned (based on brain imaging studies using functional magnetic imaging methods) was neurobiologically consistent with more effective self-regulation skills. The point is that these skills are extraordinarily important in our lives and they can be learned both at home and in school (preschool). Jonah Lehrer provides a very readable review of the work of Mischel in a New Yorker article entitled ‘DON’T’ (and subtitled ‘The secret of self-control) May 18, 2009.
Most parents help train executive functions including self-control to their children but that does not imply that this is inevitable. Adele Diamond and her colleagues published a remarkable paper in the Journal Science about 5 years ago demonstrating that executive functions can be taught successfully to socio-economically disadvantaged preschoolers. These functions are rarely direct targets of the teacher, especially not those teaching preschoolers (4 and 5 year olds). These are the very kids that can use such training because the training is a building block for so much other learning that takes place in the schools. These functions directly affect school learning readiness and measures of intelligence and as it turns out, other facets of life such as whether a child will be at risk for becoming an overweight adult.
Diamond used a training vehicle called Tools of Mind, which uses dramatic play as an intervention. The method was administered by teachers to low income urban school kids in a well-designed study (a study that assured that results were readily and clearly interpretable). The results were so powerful and clear that educators felt it was unfair to withhold the treatment from the control group.
In a personal communication Adele Diamond pointed out that Tools of Mind could also be used in kindergarten and first grade. She also suggested that there are other fun ways of teaching executive function to young kids including dramatic make-believe play, storytelling, and simple games like Simple Simon Says and Red Light/Green Light.
A year ago Adele Diamond and Kathleen Lee wrote an update and overview of the status of training of executive functions in children from 4-12 years old.
The implications of these findings along are huge.
Some references on executive functions (self-regulation) and obesity in children
Diamond et. al., “Preschool Program Improves Cognitive Control.” Science 2007; vol:318 iss:5855 pg:1387 -1388.
Diamond, Adele and Lee, Kathleen, Review article in Science (19 August 2011; vol. 333; 959-964) Adele Diamond and Kathleen
Daniels SR, Arnett DK, Eckel RH, et al. Overweight in children and adolescents: pathophysiology, consequences, prevention, and treatment. Circulation 2005;111:1999 –2012.
Dietz WH. Health consequences of obesity in youth: childhood predictors of adult disease. Pediatrics 1998;101:518 –25.
Duffy G, Spence SH. The effectiveness of cognitive self-management as an adjunct to a behavioural intervention for childhood obesity: a research note. J Child Psychol Psychiatry 1993;34:1043–50
Epstein LH, Myers MD, Raynor HA, Saelens BE. Treatment of pediatric obesity. Pediatrics 1998;101:554 –70.
Lehrer,Jonah, ‘DON’T’ (and subtitled ‘The secret of self-control), New Yorker, May 18, 2009 (26-32)
Whitaker RC, Wright JA, Pepe S, Seidel KD, Dietz WH. Predicting obesity in young adulthood from childhood and parental obesity. N Engl J Med 1997;337:869 –73.
Obesity from a neuroscience perspective
(The primary focus of this project)
There is no shortage of materials covering the topic of dieting and obesity. It was nevertheless useful for me to review what is available and organize it in a way that it least made some sense to me (and perhaps is of some value to you). However I would not have developed this website if it were simply to review the existing diet literature. My motivation and goal was to take a fresh look at familiar diet related themes from the vantage point of cognitive neuroscience an area where I have expertise and therefore fits well within my own comfort zone. The knowledge that I have gained as both a basic science and clinical cognitive neuroscience researcher provides me with some of the tools needed to think about obesity and its treatment. On the other hand I certainly have much to learn about the many facets of dieting and obesity. The question I ask myself is whether, new and useful insights emerge when looking at the complex issues associated with obesity through the lens of cognitive neuroscience. Perhaps.
Cognitive neuroscience is part of the world of mind/brain science. This world of research is huge and growing. To give you a sense of the size of that research world I would point out that over 30,000 scientist attend the annual meeting of the Society of Neuroscience and there are hundreds of journals covering an extraordinary range of topics including: the molecular events that govern brain activity; brain development; the many dynamic events that allow neurons to interact with one another; brain circuitry; genetic determinants of brain activity; the neurophysiology and neurochemistry of brain functions. Most mind/brain scientists study the brain at a very detailed level of analysis. However a substantial number of scientists are also engaged in studying a ‘big picture’ version of brain activity which includes: mechanisms responsible for brain disorders (such as psychiatric disorders, dementias etc); development (of all kinds of brain functions such as language); underlying mechanisms involved in functions such as learning, memory, emotions, thinking, decision-making, social bonding, and so on.
This is not the place to review in detail any of these areas of research. Instead I will point out (highlight) some of the areas of cognitive neuroscience research that are particularly relevant for trying to gain a better understanding of issues having to do with obesity and dieting. Some key references will be cited which might provide the reader with a starting point for looking at problems of dieting from a cognitive neuroscience perspective. In time, I intend to expand the list of cited references and the useful relevant findings that come from the cited research.
While I think a cognitive neuroscience perspective can provide us with some new insights about how to think about obesity and its treatment I need to also acknowledge that the ideas that come from this perspective have not been developed in a vacuum. In science, just like in every facet of our lives, we build on what others have taught us. It will be clear that for example, the insights gained from those who use a behavioral treatments approach to understanding and treating obesity (cited above) share a good deal in common with some of the concepts used by cognitive neuroscientists looking at the same problems associated with obesity.
Concepts used in the analysis of obesity and its implications for treatment
Executive functions (EF) which includes what is often referred to as self-regulation, and will power
a. EF functions such as self-regulation require sustained awareness and as such require a good deal of ‘energy’ (brain glucose utilization). Sustained EF depletes brain glucose and therefore is a brain resource that can be temporarily depleted.
b. Executive function skills can be taught and learned
c. Executive functions are very well understood both in terms of underlying neurobiology and the specific component cognitive operations that determine being able to carry out EF. The frontal and prefrontal lobe circuits are key players in carrying out EF
d. EF includes skills like: being able to plan ahead; skills involved in evaluating what you are doing in the here and now as well as past performance; inhibiting impulses
e. EF are what are often called top-down control functions. That is prefrontal cortex overrides activity of sub cortical regions involved in reward and emotion
f. EF functions can be impaired by drugs such as alcohol, tranquilizers and abused drugs.
Impulse control (inhibition functions)
Several brain systems are important in inhibiting (putting the breaks) on behavior. The frontal and prefrontal lobes are one of these systems. The neurochemistry of inhibition has also been very well studied (including the role of GABA, one of the brain neurotransmitters
Priming (cues for responding to stimuli such as the sight of a favorite food)
Behavior does not occur in a vacuum. Both internal and external cues (of all sorts) are what elicit behavior. Smelling the aroma of a steak on a grill, seeing a picture of the same, imagining this scene, having someone tell us about the great steak they had last night are all cues that can stimulate us to go for a steak dinner.
Taste and smell discrimination and sensitivity
Most of us can detect and discriminate between all kinds of stimuli that affect our sense of taste and smell (and other senses). However, through experience we can learn to better discriminate (notice) differences in taste and smell (and sounds and other sensory experiences). We can also ‘learn’ to ignore some of our sensory experiences. For example some people can ignore the taste of the wine or whisky they drink because there are more focused on the effect of the alcohol
Automatic compared to controlled mental operations
a. Much of our thinking occurs outside of awareness. Much of what we do has been so well learned that we can carry out an operation without effort and without conscious thought. This then means that our limited cognitive (thinking) resources can be devoted to other, perhaps more important thinking operations such as planning what we want to do next.
b. Automatic cognitive operations tend to be performed rapidly, rigidly, and are rather like a reflex. You don’t want to do much thinking about pulling your hand away from a hot stove.
c. Controlled cognitive operations are carried out much more slowly (deliberately) and are also more flexible and complex than automatic cognitive operations. Solving problems, making decisions that matter are based on controlled cognitive operations.
Reward system of the brain
The brain is well suited to register (tag) and remember what we experience as rewarding (and what feels unpleasant). This is a brain system that has been well studied for decades using all sorts of tools. We know much of the neuroanatomy and neurophysiology of the brain reward system along with the neurochemistry (such as dopamine) that is the basis of neural activity of neurons that make up this brain system.
Habit formation, learning and unlearning habits
Habits are an important facet of what is part of what we ‘know’ through experience (learning). Thousand of studies have identified the biological laws by which habits and all kinds of knowledge are learned, and the different ways in which knowledge is remembered (expressed in how we behave). Habit formation, learning, remembering have been studied in very simple living systems from aggregates of cells, simple beasts like fruit fly and of course in humans. Similarly thousands of studies have also examined how unlearning and forgetting takes place.
Emotion-driven cognition in contrast to ‘cool’ cognition
In general cognitive functions are carried out under emotionally neutral conditions. However sometimes these same mental operations are performed while we are emotionally aroused. The cognitive functions deployed to solve a problem when little is at stake, when our smarts are not being tested, are qualitatively different from the cognitive operations used in similar situations under conditions in which we are anxious, or depressed, or angry. That is, emotion-driven cognition involves a different pattern of neural activity from cognition under emotionally neutral conditions. The terms hot vs. cool cognition are sometimes used to distinguish between these two types of cognitive functions.
Forms of attention
Attention is not a single function. Some of our attention is controlled, focused and requires the use of cognitive resources that compete with other attentional demands. Some of our attention is automatic, outside of awareness and requires little cognitive capacity
Context-dependent cognition
a. What we remember, knowledge that we can retrieve from memory, how we think about a problem, how we plan or evaluate our cognition and thereby our behavior.
b. Forgetting, for example is generally a failure to retrieve what we want to find in memory not because it is lost but the context in which we are trying to remember does not provide the cues that allows us to access what we want to retrieve from memory. Likewise we often struggle to solve problem because the way it appears. Change the appearance and solutions that defy discovery suddenly seem obvious and we ask ourselves ‘Why didn’t we see it clearly before?’
c. A context can be defined in many ways such as a mood state, a setting, who we are with and so on.
A detailed analysis of how we eat, gain weight, lose weight
Cues that stimulate or control eating
- Brain structures that are the target of blood sugar cues. Low blood sugar levels signal the brain regions associated with reward (such as the insula and striatum), which is one of the basis of craving to eat. This is a universal response. The prefrontal cortex (one of the key brain structures that are the neural foundations of executive functions, self-regulation) can suppress the signals to eat. However this self-control mechanism is partially disabled in the obese which then makes it harder to resist the impulse to eat. These findings come from studies utilizing brain-imaging methods.
- Some foods stimulate our impulse to eat more. We know that eating lots of fat can make us fat. But there is more to this story that is not so obvious. When we taste fats we also activate molecules in the brain that are endocannabinoids and so we keep eating This is likely also the reason why people who smoke marijuana often have a strong desire to munch away or even to binge eat. The bottom line is that eating too much fat can help us become obese not only directly via the calories consumed but by its effect on stimulating brain molecules that trigger more eating.
- When we just can’t wait to eat. It is not just the sight of a terrific juicy hamburger surrounded by fries that break down our resistance to dive in. Conditions such as when we are in an unhappy place then immediate gratification is much more likely. A variety of studies have examined the impact of factors such as stress, depression, and an environment that is temporarily overwhelming on how we eat. Instant gratification, lack of impulse control is the response especially in the presence of foods such as sweets. Obviously you don’t need to be stressed to lose impulse control in the presence of foods that look and smell delicious. If you are someone with poor impulse control, or a child that has not yet learned a full compliment of executive functions then, once again, immediate gratification is a likely outcome
- Cues arouse impulses (to eat). Much of the time we need not even be aware of the power of cues that can stimulate eating and loss of impulse control. The presence of the container of Ice cream in the freezer is enough to break down resistance. Obviously it helps to not buy the ice cream in the first place. Removing strong cues that might stimulate impulsive eating is not practical in a world in which we are bombarded by those cues.
- What does taste have to do with cues for eating? Several studies have shown that food taste which ordinarily helps control what we eat and how much we eat does not have a similar function in the obese. Decades ago the psychiatrist Albert Stunkard who has spent his career studying obesity had different groups of both normal weight and obese subjects come into a laboratory to eat ice cream. The ice creams available to subjects varied from some of the worst concoctions of ice cream to some of the most extraordinarily rich smooth and tasty ice cream available to man. Stunkard measured how much ice cream each subject ate. Normal weight subjects ate virtually none of the garbage ice cream and the better the ice cream the more of it was eaten (up to a limit of what could be comfortably consumed). The obese were far less discriminating and ate almost as much of the poor tasting ice cream as they did the richer ice creams. Taste discrimination does not guide how much food is consumed in the obese, compared to normal weight individuals.
- A blunting in taste discrimination occurs early in those who are obese or on their way to getting there. This is the conclusion one can reach in a recent study of preadolescent subjects, some of who were on the cusp of becoming obese and others were not heavy. The plump subjects’ were much less able to make taste discriminations than the normal weight kids.
- What is the value of cues that would get someone to stop eating? Let us start with findings that will not surprise you at all. Stunkard, in a study that must be 40 years old by now, had subjects come into his ‘restaurant laboratory’ and served them steak dinners which consisted of well grilled steaks varying in size from 6 ounces all the way up to 2 ½ pound steaks. Some of the subjects were normal weight and others were obese. You guessed it. The normal weight folks did not even come close to trying to eat all the steak that was served to them (when the portion size reached a pound or more, while the obese tried to clear their plate of steaks that that would require a heroic appetite. The cues for stopping eating in the obese were a clean plate and not what their stomachs were telling them.
In another study Stunkard had subjects swallow a balloon, inflated it and connected the inflated balloon to a pen recorder that could register movements of the stomach. He asked his normal weight and obese subjects to indicate when they thought they detected movements in their stomach (like a grumbling stomach). In normal weight subjects the movement of their stomachs was reliably detected by subjects’ judgment of what was happening in their gut. Not so for the obese subjects. They could not reliably report subject motility. The conclusion to be drawn is that obese subjects either can’t or won’t pay much attention to the internal cues coming from their stomach. One might also surmise that they have trouble tracking when they are full.
Stunkard did another naturalistic experiment in which he looked at what Air France pilots ate when landing after a trans Atlantic flight. The type of meal that normal weight pilots ate when they landed was based on what had they eaten before. If they took off after eating dinner they ate breakfast when landing. This was not the case fro the obese pilots. The meal they chose was based on the time of day they landed so if it was dinnertime at their landing site they ate dinner once again even though they may have eaten dinner just before take off.
External rather than internal cues are much more potent for the obese subjects compared to normal weight individuals.
8. Priming the eating pump. Having just eaten can actually prime you to eat even more than usual. Not a surprise to note that drug cues increases the likelihood that an abused drug will be used. That is also true with food cues and this effective can be quite dramatic. It is important to note that we need not be aware of food cues that can stimulate eating for them to be ‘effective’. A particularly powerful cue is one associated with consuming what we trying to avoid. Heatherton and his colleagues enlisted dieters and non-dieters to participate in a study in which subjects were asked to rate the quality of ice cream. They were asked to not eat anything for several hours prior to coming to the laboratory. When they arrived half the subjects were given a large milk shake and the other subjects were not preloaded with a milk shake prior to then rating ice cream. The question to be answered was whether subjects would eat less ice cream when given a milk shake prior to rating what they consumed than those subjects who came hungry and were not provided with a shake. You would think that is the case and you would be right, for normal weight subjects. The findings were exactly the reverse for the dieters. Those who were given a milk shake prior to eating and then rating ice cream ate far more ice cream than those who were not preloaded with a milkshake. The mild shake primed the dieters to actually consume more than they would ordinarily ea
Paying attention
1. Attention is a function that can either be automatic or demand cognitive resources. When eating with friends and family you are likely to eat more than usual because attentional resources are used in your interactions with others rather than the amount of food you eat.
2. When attending to a cognitive capacity-demanding task it is likely that few resources are available to monitor what you eat. Sitting in front of a computer screen as you work on a complex project is a reliable to trap for uncontrolled eating. While you are concentrating on the work you are doing the automatic (and unaware) response of reaching for one more jellybean is totally predictable. Controlling what you eat, inhibiting the impulse to eat more jellybeans or potato chips takes unavailable cognitive capacity and energy.
3. Distracted eating. Of course it is enjoyable to share a meal with friends and family. The problem for those who are invested in automatic meeting will find that a distracting eating environment a setting in which they are likely to eat more than usually do.
4. Stress and attention. Stress shrinks the scope of attention. That means that you are less likely to notice things around you when stressed. In addition you are much more likely to respond automatically to all sorts of things in your environment when you are stressed. You far less flexible when stressed. How you eat is then also altered.
Self-regulation failure (and consequently poor impulse control).
1. Self-regulation failure is most frequently something that occurs under a limited set of conditions and not an overriding characteristic of how someone functions. There are many individuals who are highly controlled, self-regulators, in most facets of their lives but these same functions break down in their sex lives, how they eat, or drink. This does imply that there are some people who show poor impulse control in most of the situations in their lives.
2. There is a (delicate) cognitive balance between the extent to which subcritical (impulse-driven) and self-regulatory functions dominate cognition. Our behavior is invariably the integration of multiple brain circuitry activity. The context, conditions, timing, that are present at any given moment can alter the mix of these different brain system inputs. For example, we may be perfectly able to resist a favorite food or drink at a party but then something happens (and you pick what that might be) and our control functions fail.
3. Negative moods are classic determinants of self-regulation failures. Being in a bad mood (and that can be sprinkled with anxiety, fear, depression, uncertainty), can lead us to be more aggressive, inappropriate, drive us to use alcohol and other drugs and also to eat more and especially sweet and fatty foods.
4. Self-regulation requires energy and can be depleted. It takes energy to engage control functions such as is the case in working on a problem, or planning, or evaluating the value of what you have been doing. That energy comes from circulating blood glucose, which is the energy source for brain activity. That energy source can be depleted. If you are heavily engaged in a task that requires sustained use of control functions then there will less energy available to also fuel self-regulation that might suppress impulses to eat. Self-regulation in dieting doesn’t just feel like it requires a good deal of effort it really does require lots of energy.
Here is a simple example of the how depletion of energy required for self-regulation can spur more eating. Heatherton and his colleagues recruited young women all chronic dieters to in a study, which started with showing them ‘Terms of Endearment’. Half of the dieters were asked to try and suppress their emotional response to this dramatic emotionally arousing movie. They were then asked to rate their mood and to also rate the quality of ice creams that were served at the end of the movies. The amount of ice cream consumed was not so much related to their mood ratings but rather to whether they were asked to suppress their mood reaction to the movie. To do that required cognitive resources that were then not available to inhibit consumption of lots of ice cream.
Self-regulation, will power requires brain energy and is not an energy freebee.
5. Trying to inhibit craving requires self-regulation resources. When drug addicts are asked to try and inhibit their drug craving the areas of the brain that are the foundations of self-regulation and dramatically activated. If those resources were also required for other tasks then inhibition of craving would be compromised. While you can walk and chew gum at the same time it is hard to do two cognitively demanding tasks together.
H. Kober et al. Prefrontal-striatal pathway underlies cognitive regulation of craving Proc. Natl. Acad. Sci. U.S.A., 107 (2010), pp. 14811–14816
A.L. Brody et al. Neural substrates of resisting craving during cigarette cue exposure Biol. Psychiatry, 62 (2007), pp. 642–651
6. Self-regulation skills can be learned and strengthened. Self-regulation, or executive functions (the terms overlap) are learned early in life and continue to develop throughout adolescence. Some children do not acquire these skills early and so it turns out that very early interventions (training through games) can make up for these deficiencies. It is also possible to continue to learn and strengthen self-regulation skills (through practice).
7. Alcohol use impairs self-regulatory functions. Earlier we pointed out that negative emotions such as depression, stress, anxiety, and sense of being a failure can disrupt self-regulation functions. Alcohol (an other drugs) can also have a profound affect on these control cognitive functions. Alcohol alters the functional organization of the brain, in part by disrupting prefrontal lobe functions. It therefore is not a surprise that we eat more, binge more, with alcohol aboard.
Eating as an addiction: The role of the brain reward system
1. Addicting substances (food, drugs, etc) activate the mesolimbic dopamine system in the brain (the reward system). If someone is addicted to a substance it will trigger his or her reward brain system. One of the key foundations of addiction is the automatic activation of this brain center. Cues associated with their addiction are the triggers for the activation of the brain reward system. The cues associated with an addiction need not be part of subject’s awareness in order to trigger the brain reward system. Another interesting but not surprising finding is that dieters who break their diet are even more sensitive to food cues. Hundreds of studies have provided the details of how all this happens.
While the reward system plays a role in all addictions each form of addiction also has some unique features in how that role is played out on the addiction stage. So for example, while the way in which the reward system is activated and how it interacts with other brain circuits shares a good deal in common with cocaine, or alcohol or narcotic addictions each also has a somewhat unique signature of affects on the brain. This follows from the fact that drugs of abuse are chemical substances that directly interact with neuronal neurochemical events.
2. Tipping the balance between the reward brain system (sub cortical system) and the self-regulation, executive functioning system of the brain (prefrontal lobe functions). In so many instances in our lives we are in a cognitive battle between our impulses and our self-regulatory functions. A bad mood, or a strong cue, or a temporary failure on a diet can allow impulses to overwhelm our sell=regulator functions. Likewise a sense of success, feeling good about oneself, optimism in place of depression can allow us to mobilize self-regulatory functions in the control of our behavior. Of course it is important to let impulses fly free but to do so when they are not likely to be destructive consequences. Do you really think it wise to run away with your seductive secretary?
Mapping what to do to lose weight and keep weight gain from returning
Your goal is to change how you eat. Here are some things you can do that would be helpful. Please note, the list of suggestions listed below needs elaboration. I will do that in the next few weeks. For the present the list is one that is my working reminder of what still must be filled in with details.
Keep a diary. Why? Effective dieting takes place in several steps. The first is to make explicit (make you aware) of how you eat. That means that you must become very familiar with when you eat, how fast, what you eat, what the food tastes like, what conditions promote your unhealthy eating. You must take note of all this and that takes time and some discipline. You will find that much of how you eat is automatic and outside of awareness and the very act of keeping a record of how you eat is a way of making how eat explicit. This is a learning process, one in which you are making eating less automatic and more explicit. This becomes the ideal opportunity to change how you eat. At first this is done using executive functions, which are needed to evaluate, plan and monitor how, eating behavior is to be changed. Whatever changes are made must be very well practiced and in time these new eating behaviors will be automated replacing the older version of how your past eating style.
This is exactly the course of learning, of cognition, that is the basis of acquiring any kind of expertise. The goal is to change an expert at unhealthy eating to an expert at healthy eating. You have to commit lots of time and effort. There are no shortcuts.
While eating keep other activities to a minimum. Why?
Eat slowly, strategically and deliberately. Why?
Be proactive. Why? Anticipate the power of strong cues that can trigger out of control eating.
Reward yourself well and often. Avoid misinterpreting diet failures. Why?
Set realistic goals which means very small ones. Why? What if I told you that my goal is to run a marathon that is scheduled 7 months from now. What if I told you that if I put my mind to it then I know I can do it?
Imaginary goals are not real. Why they lead to failure?
Avoid being seduced by promissory notes and smiling faces. Why?
If possible do the diet work when your mind is not in overdrive. Why?
Controlling cues while on a diet. Why? A daily weigh in as a cue for telling us how we are doing on a diet. The evidence available tells us that a daily weigh in can help keep us dieting effectively. The folklore is that it doesn’t make sense to weigh oneself each day and that once a week is sufficient to monitor weight. The evidence does not support that notion. The obese trying to control weight need all the cues they can get to help them monitor eating.
Procrastination invariably works against an effective diet action plan. Why? Many studies have demonstrated that the quality of the work completed by procrastinators is inferior to that of individuals who can plan ahead. The deadline that appears before us with no time to spare is stressful. It sets up conditions in which cool cognitive is replaced by emotion-driven cognition. Under those circumstances evaluative functions are less effective. We are less able to plan strategically. Quality options available for solving problems and making decisions is much more limited. Our thinking is more reflexive than reflective. Leaning is impaired. Dieting takes all of the cognitive skills that you have available and compromising those processes is not in your best interest.
Try not to drink and eat. Why?
Move food and eating from the centerpiece of what is fun your life. Why?
Be a patient learner. Why? Changing how we eat is complex and must take place in several learning and unlearning steps.
Unedited supporting notes (and bibliography) that are to be used as background for the talk but also serves as the foundation for the development of this collaborative blog
A. Vignette: A few months ago I was walking by an elementary school around 3 in the afternoon. I saw my neighbor who had just picked up his 9-year-old son from school. Coincidentally I had a camera with me and so he asked whether I might take a picture of him with son standing in front of the school. Later that day I uploaded the picture on my computer, stared at it and then sent him an e-mail with the picture attached. I found the picture more shocking than the scene in ‘real life’. They stood their smiling at the camera. The father was morbidity obese and the 10-year-old son a bit chubby. I thought that the kid must have known that he was getting heavy and knew that the father had tried all kinds of diets, lost weight and regained it, often with a vengeance. I thought about that day when the terrific kid would become as fat as the father? Can we rewrite the script of this awful miserable and deadly play? Can we somehow get the father to lose weight and keep it off?
Maybe I am over reacting. I would be happy to be of help. How much useful knowledge do we really have that can be applied to the problem of eating disorders and obesity? Even bit and pieces of useful science based evidence would be better than nothing and far better than packaged nonsense.
B. Changing patterns of uncontrolled (automatic) behavior: Automatic eating is just one form of many kinds of automatic behavior. How do we take advantage of cognitive neuroscience knowledge that can deautomate maladaptive thinking, decision-making, behavior. How should we use what we know about habit formation and reward? Is it worth exploring the role of tipping points and capitalizing on cognitive momentum?
C. The role of the reward system in addiction: Lots of material to be added on this topic. No doubt that Food addiction shares most of the same neurobiology as other addictions (such as cocaine and alcohol addictions). An addiction is associated with a rewired brain. Relapse is as common in dieters as in those who temporarily abstain from cocaine use. The brains of the obese have been rewired to support their food addiction. Fat ‘loving’ brain cells are also part of the picture in the obese. Looking at food addiction as an addiction just like to cocaine demonstrates (based on brain chemistry) why so many dieters fail. Brain imaging studies show that brains light up to favorite foods in the obese in much the same way as cocaine related cues activates brain circuitry in cocaine addicts.
Food addictions result in rewired brains (concept that is part metaphor and part based on a diverse set of scientific findings. Of course any learning changes the brain rather than the liver. However addiction-related rewiring is more dramatic than the neural changes in response to everyday experiences? A food addiction places the brain’s reward system (circuitry, genetics and chemistry) center stage in learning and habit formation and therefore is the kind of powerful learning that cannot easily be rewritten. For example, a recent study shows that eating fatty foods can actually stimulate the sprouting of new brain cells (that are ‘fat loving’) and these cells can trigger weight gain (in animal studies). Color the rewired brain with deep red strokes.
An additional consequence of the rewired brains in the food addicted obese is that cues for eating and stop eating are automated and are no longer under conscious control. Food cues (pictures, smells, ads, supermarket aisles, trigger reflexive responses without access to controlled cognitive functions (such as planning, inhibiting eating, assessing consequences, monitoring what is going on while eating). The obese have become expert eaters and by that I mean that they have ‘successful’ automated eating and blocked cues for satiety. This has some important treatment implications.
D. Overeating is highly cue dependent: Topics to be expanded include; Cues for eating, inhibition, hot (emotional) and cold cognition and role in decision making, nature of habit and habit strength, self regulation and resource depletion (role of prefrontal and sub cortical balance), instant gratification.
E. The diet industry is big business: Expand this an point out everywhere you turn there are new products and lots of hype…i.e., new company called Life-size a weight loss company that emphasizes portion control by selling plastic measuring devices geared for different food groups like carbs, meats.
F. One fat may not equal another: All fats are not the same. Different types of fat (brown, white, yellow). Stimulating brown fat production can be helpful in weight reduction (new products are now in the production and test phase of development). Treatments that stimulate brown fat (in contrast to white fat) might help the obese to lose weight. Targeting brown fat and an exercise plan can increase metabolism, get rid of yellow fat, and replace it with healthy brown fat.
Brown fat, found in much smaller amounts in the body, actually burns calories to generate heat. Babies and children have a relatively high proportion of brown fat to help keep them warm, but as we age, we lose it.
The Brown Fat Revolution, according to Lyons, is not so much a weight loss diet as an eating and exercise plan designed to help you increase metabolism, get rid of yellow fat, and replace it with healthy brown fat.
Brown fat, unlike white fat cells, which get their name from the excess lipids they store and whose relatively few mitochondria transfer energy from the lipids and sugars to the energy-storing molecule ATP, brown fat cells’ many mitochondria contain an “uncoupling protein” that allows them instead to release the energy from sugars and lipids as heat—to warm hibernating animals, Researchers think that by increasing the numbers of brown fat cells in adults, or by activating those that already exist, they will be able to help people burn calories, shedding extra pounds as a result.
G: Hormone treatments can be useful (in animal studies) for weight reduction but impractical in humans. Candidate interventions such as somatostatin, testosterone, growth hormone, insulin have all been extensively studied.
H: Calories are calories are calories. Research from the Rockefeller University has AGAIN shown that what matters are total calories consumed and burned. If you take in more than you burn you will gain weight and certainly not lose weight. Need to provide lots of details here (based on Gina’s article on the work of Jules Hirsch, Univ. of Rochester, and summarized in the Science Section of the July 10, 2012 issue of the New York Times).
I. The cues for eating in the overweight: This requires an extensive section of details starting with classic studies of Albert Stunkard (35 years ago) to similar work by folks like Heatherton and other studies that keep popping up like the German study showing that even in the young taste discrimination in the obese is impaired compared to normal weight kids.
Stunkard used a set of simple clever studies to show that in the obese there is a lack of food taste discrimination, inattention to internal and external cues that would ordinarily have folks stop eating ( Albert Stunkard (who has been head of the Weight and Eating Disorders Program at the Univ of Penn; stunkard@mail.med.upenn.edu ).
Here are some of the themes (findings) of his scientific research papers published 40 years ago.
- When you get normal weight and obese folks to report stomach movement and gurgling when they occur, normal weight folks are accurate reporters but this is not the case for the obese. Incidentally the movement of the stomach was measured with a primitive device, a small balloon that is then blown up in the stomach of the volunteer study participants. A pen recorder is attached to the balloon and captures the movement of the stomach
- Various qualities of ice cream are prepared and presented to fat and normal weight subjects for the eating pleasure. The ice cream quality varied from something close to sweetened icy muddy like substance (resembling chocolate in color) to the best of the best huge fatty smooth huge flavored ice cream fit for a queen. Your guess is correct. The obese ate almost as much of the garbage ice cream as the best of the best and that was very much not the case for the normal weight volunteers.
- The how much steak can you eat experiment was simple and the results were crystal clear. Bring subjects into the laboratory and serve a fabulous steak that varied in size (in quarter pound increments) from half pound to two and a half pounds. You guessed it again. The obese tried to clean their plates into their mouth even when presented with a heroic sized steak.
These types of differences in response to cues associated with eating between the obese and normal weight individuals are supported by brain imaging studies. For example, seeing images of food dramatically activates the reward areas in the obese and suppresses activity in severely underweight people see; http://www.sciencenews.org/view/generic/id/339711/title/Extreme_eaters_show_abnormal_brain_activity
The priming research of the Heatherton group a Dartmouth is most pertinent for this section of the blog. Bottom line of this research is that in the overweight consuming rich sweet foods primes them to eat more of the same, even more than they would ordinarily consume on an empty stomach.
So, the evidence is pretty solid that the cues for eating and ceasing to eat are very different for the obese and the normal weight subjects. Does that imply that interventions like controlling portion should work? With some individuals it does do so but not the majority of folks.
J. Who is fat? Lots of measures and new ones emerge all the time. We moved well beyond a weight to height to gender to age index. Recently one more measure has joined the crowd, one that measures body shape. That measure turns out to be a pretty good predictor of premature death through the marvels of obesity. I guess the shape index is a bit more precise than how much fat is around your middle. So what. The obvious facts are accessible to all of us. Obesity is a killer and it is rampant. This is a rich country where food is plentiful and relatively cheap even if you are poor.
K. Role of exercise in changing DNA and the role in weight reduction: (to be explored)
L Diets here there and everywhere: Diets have been around forever. There are scores of them and each is seen as the most effective intervention for reducing girth and implementing healthy eat9ng habits. My guess is that dieting books are the most numerous volumes in places like Barnes and Noble (right after books on finance, and computer related subjects). They generally tell the readers that following the prescribed diet is relatively easy, even fun and delicious, and success is assured rapidly and forever. No comment needed. The books (and programs) also deal with topics that are in part pseudo science, such as not all calories are the same (which they are not) and that some of our fat cells are good (brown fat) but not the kind of fat cells in the obese. The diets have been reviewed over and over. The most recent review argues against carbs in favor of fats and protein but then other books suggest that Mediterranean diets (carbs and good fats and oils are the way to go. All diets can work but dieters are as likely to relapse as cocaine addicts. Here is a partial list of the most frequently used diets and diet programs. Quite an industry that includes, among other names hat promote their ‘unique and effective’ diets include; Atkins; Best Life Diet; Biggest Loser; Cabbage Soup; Hallelujah Diet; Jenny Craig; NutriSystem; Ornish; South Beach; 3 Day Diet; Weight Watchers; Zone; Brown Fat Revolution
Each plan is highly detailed and generally needs to be rigidly followed. Can any of them be translated into a lifelong change in how and what we eat? The evidence does not support reliable weight loss that is retained by those who use these diets.
Some diet routines suggest writing down everything that one eats in the course of the day (Weight Watchers on line). While this may be of some value writing down, noting what is being eaten as one eats may be a better strategy for making eating behavior part of awareness.
Controlling eating in a social context has also been found a useful addition to some diet plans. Dieting with others (meeting together at weigh INS …sharing successes and failures, using social support and pressure can be helpful in a number of addictions (i.e., AA). For some individual competition can be a spur to weight management.
M. Hormones and obesity: The notion that getting fat may be based on a hormone imbalance is not totally unlikely just, on average improbable. For example, in a study using mice as subjects reducing the somatostatin (hormone) levels reduced weight and that makes sense since somatostatin activity is linked to two other hormones—growth hormone and insulin-like growth factor—that promote weight loss (paper published in by Keith Haffer in Journal of Animal Science and Biotechnology)
While we are on topic of hormones and weight control we should also not that in another study, this one in men receiving testosterone. Men treated with testosterone (for other than weight loss reasons) consistently lose weight. The results were reported by Farid Saad on June 23 at the Endocrine Society. At the start of the study nearly all of the participants, were overweight or obese and lost 36 pounds on average over the course of five years.
N. Can the study of habit formation and unlearning habits be usefully applied to dieting? We know a great deal about habits, which have been the focus of study for well over a century. So much of what we do can be labeled habits or very well learned behaviors that persist in large part because the behavior is automated, carried out without much awareness. The heavy hitting eaters engage in habits (automated and highly rewarding behavior) that helps keep them fat such as eating too fast, not tasting what they eat, piling heroic amounts of food on each fork filled motion, as well as continuing to eat whatever is on their plate regardless of amount. Some of these eating habits have been the target of interventions in the obese. With persistence it should be a reasonable goal to train someone to eat more slowly and taste his or her food.
O. Fooling the brain: The brain can be fooled into thinking artificial sweeteners are the real thing. We have known this for decades and now we have some neurobiological evidence that supports behavioral observations. I remember when I was a young student at Hopkins we discussed studies showing that rats will work their tails off for artificial sweeteners and even then we all shrugged. So what does that mean for weight control? Are we fooling our brains and therefore of course ourselves.