Friday, April 8, 2011

Eating Disorders, Obesity and Addiction

I've been meaning to do more on eating disorders for a while, but I find the research frustrating.  As do eating disorder researchers - see, within eating disorders even more than in some other areas, the diagnoses proscribed by the DSMIV don't really fit the symptoms most people have.  There are three "official" categories - anorexia nervosa (AN) (restricting eating, underweight, obsessed with body image), bulimia nervosa (BN) (bingeing and purging via vomiting, excessive exercise, or laxatives, typically normal weight or fluctuating weights, body image issues), and eating disorder not otherwise specified (EDNOS)(anyone who seems to have an eating disorder that doesn't quite meet the other criteria).  Most people with eating disorders fall into the last category, simply because many people with primary anorexia also binge and purge in some way, and bulimics will often have periods of restriction.  Even worse, there is an entire category of eating disorders that has no "official" diagnosis, the binge eating disorders (BED) (bingeing without restricting or purging, patients are often overweight but some are normal weight), and it is actually more common than anorexia. (These numbers are approximate as many folks with eating disorders don't seek treatment, but the estimates are that 0.5% of the adult Western population has AN, 1% has BN, and 3% have BED.  There are no estimates for EDNOS.)

When you review the literature for "evidence-based" treatments, there really are none for EDNOS (1), simply because research has focused on AN and BN.  In anorexia, there are a few firm things to recommend - if severely underweight, refeed under supervision, and other treatments don't work particularly well until the starvation is to some extent reversed.  For young people, family therapy is recommended.  In bulimia, there is a particular type of cognitive behavioral therapy that is specific for the disorder and has good evidence base.  

Eating disorders are among the most deadly of psychiatric disorders in the short term (anorexia is probably fatal in 5-10% of cases, though this number is dropping as acute treatment is getting better, whereas BN and EDNOS have a mortality rate of about 3.5%, and people with all the disorders, including BED, have a higher risk of suicide) - but the good news is at 10 year follow-up, between 70-80% of people with the disorders no longer have symptoms.

What is particularly frustrating about eating disorder literature is that no one has a real clue (backed by solid evidence) as to what causes them.  There are some genetic links, some common psychologic features and environmental risk factors, and it is likely that people with low amounts of serotonin and dopamine in certain areas of the brain are more vulnerable to developing eating disorders.  

My own suspicion (speculative, but sensible) is that the combination of societal pressures to be thin and our modern industrial diet's terrible track record of putting on fat lead to very common restricting behaviors, which basically makes everyone a member of a little Minnesota Starvation Experiment, only we are not locked down, so we continuously restrict, worry about exercise, then begin to obsess about food and have anxiety and depressive side effects, then we (quite sensibly) cave in to the evolutionary imperative to eat, regain the weight,  etc. etc.  A particular subset of people, often young women who perhaps face the most societal pressure, will develop extreme behaviors and become eating disordered.  Thus my conjecture is that the industrial food is the problem, and wholesome unprocessed food (get rid of the excess sugar, excess linoleic acid, and gluten grains) a large part of the solution.   My stance is actually as unproven as it is controversial - as many people with eating disorders restrict varieties of food, during recovery it is common practice to teach people to eat "everything in moderation" (though focusing on healthy, nourishing food, of course), so to suggest restricting whole categories of food again without a solid evidence base could be seen as feeding into the disorder.

But there is an issue with "everything in moderation," I think, putting aside the entire "paleolithic" nutritional paradigm and the neolithic agents of disease causing obesity in the first place. And that is that eating disorders are addictive (2).   While some folks with addiction can actually, eventually, moderate their intake of the addictive substance, most people do better, at least for a while, with complete abstinence.  Obviously one cannot completely abstain from food - but if we suspect the neolithic agents as building an addictive cycle neurochemically in the brain (and this is definitely speculation, but an educated guess, I would say), then it would seem that getting rid of them in the diet would be of obvious help.  Once the situation is stabilized, and a more natural and realistic relationship with food and body and diet are adopted, then it would make sense to adopt more moderation to make life easier and less food-obsessed.  But everyone is different - some people get very despondent with the idea that anything is off-limits.  Treating eating disorders like every psychiatric condition requires some common sense, flexibility, and innovation.

Let's get back to my addiction angle for a minute, and, while I'm going to spend some time in a second post focusing on the neurobiology of binge eating, today I'm going to drop "eating disorders" and look at a new paper called Neural Correlates of Food Addiction.  This study is actually about food and obesity in general.

The bottom line in America - 1/3 of adults are obese.  Obesity-related disease is the second-leading cause of preventable death, and most obesity treatments are unsuccessful, with patients regaining all the lost weight within 5 years.  Food and addictive drug use both result in the release of dopamine in the mesolimbic regions of the brain (at least in animal studies), so one gets a sense of "reward" and happiness from eating.  Obese versus lean individuals show greater activation in the addictive behavior centers of the brain in anticipation of receiving "palatable" foods (obesity and food researchers here typically mean sugar and fat and salt - my still-unproven conjecture is that the massive excess of linoleic acid, fructose, and the easy, cheap availability of fatty-grain chips and the like and sweetened grain desserts are the issue, and while a gorgeous bone marrow dressing on a salad and a delicious steak would also light up the reward areas of the brain, it is part of the natural order of things to shut the reward cycle off if our bodies reach a certain level of fat stored on hand.)  And, interestingly, one finds this to be the case in obese individuals and people addicted to drugs - obese people anticipate food intensely, but when the actual food comes, they have less enjoyment (in general, the reward brain areas light up less) than someone who is lean.  The same is true for drug addiction - the brain seems to like the anticipation much more than the actual event.

In the study, 48 young (human) women with an average BMI of 28 were selected from women enrolled in a program "developed to help people maintain a healthy weight on a long term basis."  Those with history of eating disorders, head injury, or current smoking, illicit drug use, or psychiatric diagnosis were excluded.  Each participant was measured and weighed and took some tests assessing their level of food addiction (the research standard is a 25 item Yale Food Addiction Scale.)  The test among these young women had a normal distribution.

Then the participants were put into an MRI for a baseline measurement after fasting 4-6 hours (no caffeine either).  Then the women were exposed to pictures of a chocolate milkshake or a picture of a glass of water for a few seconds.  Thereafter they received one of two "deliveries" - half a milliliter of chocolate milkshake* or a calorie-free tasteless solution meant to mimic saliva.  All of this was randomized - some women got a picture of water then saliva, some milkshake picture then saliva, some water picture then milkshake, etc.   And 40% of the time, no "taste delivery" was made to give the researchers an idea of what a scan would look like without the paired stimulus.  The taste delivery occurred via some sort of tubing system within the MRI scanner itself, which is kind of a neat trick.

Results!  The women (lean or obese) with a high level of food addiction on the scale test showed more activation of brain centers associated with addiction and reward in anticipation with the milkshake picture, and less activation with the actual milkshake.   This is pretty solid human evidence that there are certain people who are truly addicted to chocolate milkshakes.

Interesting tidbits from this study - the addiction scores were not associated with BMI of the participants (average age of 20.8).  However, those with high scores on the addiction scale test were far more likely to have periods of binge eating, emotional eating, and "problematic eating attitudes."   The researchers felt that the young age of the sample might mean that the lean women with a high food addiction score would have increased risk of obesity, as older obese adults tend to have higher food addiction ratings.  I suppose time will tell.

The main problem with the study is that the researchers did not measure hunger in the participants.  Though they all fasted about the same amount of time, some may have been hungrier than others, and hungrier people have greater food reward signals in the brain.  The other limitation I see is the selection in the first place - rather than selecting random young women from a college campus, for example, they chose those enrolled in a healthy eating seminar.  

Well.   What did we learn, really?  "Highly palatable" food can be addictive to certain susceptible individuals.  Usually things are highly palatable because they are somehow good for us.  I have the feeling that in an environment without the neolithic agents of disease, the food reward system would work as planned, just like the sex reward and the exercise reward.  Jack up the system with weird chemicals in excess of anything we ever experienced in evolution - like heroin, tobacco, or ho-hos, and some people will develop a problem.
* Obesity researcher milkshake recipe:  4 scoops Haagen-Dazs vanilla ice cream, 1.5 cups of 2% milk, and 2 tbs of Hershey's chocolate syrup.  Personally I would recommend using some variety of artesian or homemade reduced sugar chocolate ice cream and whole milk without the syrup ;-)  Also whipped cream and chocolate shavings on top.


  1. Very cool! Your concluding paragraph leads me to recommend that you file this post under the category of Food Porn. ;-)

  2. Eating disorders are of some interest to quite a few other conditions which may potentially hold some clues to some shared mechanisms. Way back in 1983, Gillberg in the British Journal of Psychiatry started talking about co-morbidity of anorexia and autism (either in person or in family). More recently researchers at Kings have been talking about shared 'cognitive' profiles (Oldershaw et al) focused particularly on test results pointing to 'attention to detail'. What this suggests is that there may be an underlying 'phenotype' to AN similar to other conditions (I can't say for BN cos' no real research). Whether this is genetic, environment or both (most probably) is the million dollar question. Whether our diet is contributory to this requires perhaps another million in the bank.

  3. Thank you for this post. As a former sufferer of anorexia & a current sufferer of EDNOS, I am grateful to see sensible posts like this, focused on the biological contexts of eating disorders. (The issue is often clouded by rather badly framed Cartesian notions of a mind/body split.) My own experience has suggested (anecdotal evidence alert) that the one of the most crucial steps to recovering from an eating disorder lies in addressing problems of chronic malnourishment (& attendant deficiencies in brain chemistry)through a Paleo 2.0ish approach.

  4. Isn't it relieving to acknowledge that an ED is not wholly (if at all) caused by our own (ir)rationality/desire to be slim, but rather by a biological mechanism?
    I really like your attitude Emily: Humans are not broken!

  5. @Ted, I agree! But I'd rephrase your final sentence as "Humans are not broken by default" (to quote Angelo Coppola of Latest in Paleo. Because we can be and often are broken by Conventional Wisdom or other conniving forces.

  6. Good post. Earlier comment of mine swallowed up by library network...As a former ballet dancer and sufferer in the past,I have continued interested in EDs of all types. Have a chapter on EDs in an upcoming Fortress Press book on psychiatrists and pastors working to support family members of patients in treatment.

    It's a case of both/and with the biological and psychological explanations. Almost always are themselves obsessive way beyond mild personality trait. Obsessive verging on the perseverative (as in autistic). I have an autistic kid, and several mood disordered family members. There are some co-morbidities, at least within families. Bipolar/autism/EDs/personality disorders. And not simply from assortative mating. To be fair, the only people I know with EDs do fit into the traditional profile of white, rich, over-educated females from pushy professional families, but I gather that plenty of other groups also have the same kinds of family pressures nowadays (perhaps from similar biological/temperamental mixes in the parents?). I suspect that many Tiger Mom Wannabees have anorexic kids. Not that being a TIger Mom turns your kid anorexic, but that being hypomanic and driven and obsessive stems from a particular kind of biology likely to have been passed on to one's kid, an harsh upbringing a la TM may do little to discourage self-punishment by the offspring...

    Carolyn Knapp's writing is quite beautiful and enlightening on her eating disorder "Appetites; Why Women Want" and also on her drinking problems "A Drinking Life". She was a spectacular writer, a psychiatrist's brat, she died at 45 of lung cancer. She also wrote about humans and dogs. She really gets the interconnections between appetites for love, and food, longings for recognition and desire to discipline oneself, and yet one could use her insights even if one believed it was all biological.

    My only reservation about a person who has had an ED going on the Paleo diet is that I don't really think the addiction is to the "bad" foods per se. I think eating disordered people have addiction prone personalities because they are obsessive psychologically, as well as biologically sensitive to cruddy food. Also have problems alternately with not feeling pleasure, and with one moment being able to endure starvation better than typical people, another stage of their life, not ever feeling full, and binging. IN other words, their satiety mechanisms are out of wack. Just as alcoholics' handling of booze is out of wack.

    Also, as someone who has struggled to live more normally around food for some 30 years since getting over youthful anorexia, I am wary of adopting any dietary regime (and suspect that many recovered ED types also might be) that might trigger those old obsessive tendencies to divide food into "Good" and "Bad", and to be always saying No to longed for things, and to be sharply differentiating oneself from everyone else, and to be once again purging all forbidden substances from one's house. A normal person might not find such an activity a big deal, but if one used to be anorexic, the fear might be of not being able to be moderate about it...By definition, people with EDs find it difficult to do anything in moderation.

    Having said that, I was also just reading something about leptin and depression and weight gain and thinking that probably some modified paleo diet is better especially for people prone to depression and eating disorders, even more than typical people. So I think the trick would be how to do it without a relapse of the ED. Sorry to belabor the point...(of course, with hard core anorexics, that would be a feature, not a bug, that you could sell it to them as a weight loss diet...:)

  7. I have to say I am a big believer in mindfulness eating such as in the book Savor - - but I've yet to have an eating disordered patient really benefit from intuitive eating. I think fixing what you are eating must come first, before figuring out how to eat mindfully.

    And I must admit in my own experience I don't care much what I eat - but when I was pregnant or early Breastfeeding the food obsessions were really amazing. My taste and senses and smell were different, cravings, very different experience. I might have stolen a snickers out of a drawer of I found one, when normally a snickers would have no appeal... the different cravings with respect to different situations and hormones is really quite striking.

  8. I have only worked directly with a couple of young women who had eating disorders.

    Typically, nutritionists do not get to do much work with people with eating disorders as they are referred into the Eating Disorders Unit which is part of the mental health unit within the hospital system. These eating disorders are treated as a psychiatric illness first and a physiological illness second - the latter always follows the former. I have a tendency to treat them in the opposite direct and this is exactly the approach I took with the BN patient I worked with. At this point in time, I hadn't fully embraced the paleo paradigm, but I was certainly well on board with getting people to eat gluten free. With this particular patient, taking her history and getting a family history, I was suspicious that there were gluten issues there. I managed to get her mother to refer her for testing, and sure enough she returned a positive tTg test, as did her sister & mother. We eliminated gluten, undertook a period of nutrient replenishment with plenty of fish oil, zinc, magnesium, etc. Over a period of a few weeks, her anxieties subsided and she became more focused & calm.

    Now this is a n=1 case, so I'm not suggesting that everyone who has an eating disorder has gluten sensitivity, but I'd want to eliminate all of the neolithic agents you have mentioned Emily, and embed a paleo-type diet alongside some of the cognitive behavioural therapies that also occur to see whether this takes. Unfortunately, having seen the diets that are used in refeeding through the EDU here, they are invariably grain/PUFA-based.

  9. Is veganism classified as EDNOS? ;-) I like what you said at the end of Your Brain on Ketones post about not recommending IF to people with eating disorders. It seems like some people try to employ IF in the context of fat loss and calorie restriction. This just seems like the first step down the eating disorder slope. That is to ask rhetorically, at what point does fasting become self induced starvation/restriction?

  10. Paul - of course there a lot of food restriction and pickiness among autistic children - and I've seen (young) teenaged girls on the Aspergers side who seem to have full-blown anorexia - yet no body image issues. I wasn't aware of the genetics and I would like to look into that more. Very interesting.

  11. As to my overall approach to eating disorders in my practice - I am of course conservative in my practice and explore all sorts of interesting ideas in my blog. For example, you might think I use ketogenic diets for bipolar disorder - I don't, typically, as there are no studies and the two case studies in the literature were failures. That said, I do tend to use nutrition in treatment of eating disorders, but my focus is very individualized. Keep in mind I see adults, and typically an eating disordered patient will have had other treatment and has another therapist, as the disorder was usually worse in her youth, though not always. And of course for the most part the disorder doesn't get so out of hand that the person needs to be hospitalized - if there is a hospitalization, typically it is for something else, like depression.

    So for anorexic restricting types - they tend to avoid carbs (except fruit or some sugar) like the plague so gluten/grains is rarely an issue. A typical couple of meals would be fat-free greek yogurt, a string cheese, and an apple. Some force themselves to eat breakfast daily as part of a routine of eating, but I would say they IF as much as possible (though they don't call it IF), and meals are often skipped (they try to go for as long as possible without eating). Eating is always an issue, as food is basically the enemy. Nutritionally I try to get them to eat more fat, talking about the brain and how it needs fat (the easiest thing to start with is usually full fat yogurt), and then also focus on micronutrients. If she has children, we talk about nourishing food for them, bone broth, chili, B vitamins, zinc, etc, and what they might eat and what she could eat. Again, it really depends on the person. Some do better eating regular meals at certain times as it decreases the anxiety, some do better just trying to get nutrient-rich food in when they do eat. Most stay slender but not skeletal. I would say most of the adults I see have had it for 10-20 years or more so it is pretty ingrained. Mostly they have learned to avoid chronic cardio, but in general are focused on being small, so often won't lift weights. Sometimes they will do yoga or pilates. If they are sleeping and eating and maintaining weight, I encourage the yoga, especially, for anxiety and health benefits. (Again, these are generalizations - and everyone really is quite different).

    For bulimia and binging there is often a lot going on… but I do focus on good nourishing food, in bulimia food she can keep down, and avoiding the classic easy-purge foods like oatmeal or a big fluffy loaf of bread or rice or ice cream (depending on the person). Binging tends to involve carbs or fast food (going from one drive through window to another to another… or chocolate). Here the mindfulness and mindful eating can come in, but it is difficult. So the work is very similar to addiction work - cognitive behavioral stuff about avoiding binge or purge situations, coping with cravings, behavioral analysis of previous binges and how it could have been prevented, anxiety regulation, etc, appropriate exercise.

    There are some interesting cases of specific night eating - usually this is bread or cookies or something. Sometimes it is medication related or a sleep problem so you want to rule that out first, but in a couple of cases (one of them in someone with celiac who could not stop night binging on bread), I have actually stopped night eating by using naltrexone, an opiate blocker, for several months, then once the cycle is broken we've been able to stop the medicine and the person avoids wheat thereafter. That is not an FDA approved usage, of course, but typically the person is very desperate by the time they see a psychiatrist for night eating, and the risk of a few months of naltrexone is not high. I make it clear we are a little off the known grid doing that, but discuss the rationale.

  12. js290 - I do think IF is a useful tool for developing a healthy relationship with food - being okay with being hungry for a few hours, being able to eat a bit more fat without taking in too many calories with fewer meals in a day, but in some people, IF can cause a lot of anxiety and hunger can trigger binge-purge cycles, so I think it should be done with care. IFing is sort of the last piece to fall into place as focus on eating real nourishing food and good nutrition and avoiding toxins should come first, especially with eating disorders.

  13. "What is particularly frustrating about eating disorder literature is that no one has a real clue (backed by solid evidence) as to what causes them."

    True. Since you seem to favor an evolutionary approach to the study of health and nutrition, though, I'm surprised you didn't mention the "adapted to flee famine" hypothesis for the evolution of anorexia nervosa:

    I find this a compelling model -- it makes sense of the whole spectrum of AN psychopathology, as seen in clinical practice (as well as observed in a controlled setting in the Minnesota Starvation Experiment). It also explains the documented cases of anorexia in throughout history, and the presence (albeit with lower rates) of eating disorders in non-Western countries -- both of which weaken the case for society's obsession with thinness as a major contributing factor. As an (ex-)sufferer myself, I have always been skeptical of this kind of cultural explanation. I find it much more plausible -- and more consistent with the fact that most chronic anorexics actually have little interest in looking like runway models, and the imperative to not eat is often even stronger than the desire to look a certain way -- that the "fear of gaining weight" motive held by anorexics might just be the patient's higher cortical centers (the "interpreter module") trying to rationalize a genetically-derived compulsion to restrict food. It does so by searching for cues in the environment (i.e., in the Western world, the pressure to be thin) that could convincingly make sense of a behaviour that is beyond conscious appraisal. Thus, when mental health practitioners blame (in part) the media's beauty standards for causing eating disorders, they are really taking for true the anorexic's confabulations!

  14. Speaking of IF, I agree with your intuition that it should be absolutely off-limits for eating disorder patients. The reasons are obvious -- for an anorexic's brain, no matter how far in the recovery process, IF (of the conscious kind, not accidental) is just the "health community"-approved equivalent of restricting. It's like the doctor's giving you a free pass! (In my opinion, better not even mention it.) In the evolutionary framework, it is likely (but I'm just speculating) that people with a genetic predisposition towards developing anorexia are very sensitive to the threat of famine -- going long hours without eating will easily trigger the anorexic adaptation mechanism (and thus the symptomatology) to set in relatively quickly. On the other hand, a regular eating schedule (not necessarily comprising of as much as six meals as usually prescribed) is more likely to signal to the hypothalamus and related structures that food is abundant and will reliably keep coming.

    As for the question of whether to encourage patients to eat mostly whole, unprocessed foods in their recovery, I'm torn between two sides. Poor nutrition (especially hyper-palatable food with addictive potential), as you have persuasively argued, can exacerbate bulimic tendencies, and it certainly won't help with the depression and anxiety that often go hand in hand with eating disorders. However, I have to second the caveat expressed by Retriever in one of the comments (April 8, 2011 at 5:14 PM): restricting food types (as opposed to merely quantities) is a behavior the eating disorder loves to latch onto. Even adopting a fairly liberal Paleo-style diet makes it a struggle to give up the "safe vs. evil food" mentality that dominates the patient's life; as Retriever described, anorexics really struggle with the idea of moderation and with dichotomous thinking. Another BIG reason I see against implementing Paleo nutritional guidelines in recovery is that, unless you happen to convert all of your social circles to Paleo, following a diet will feel very isolating -- furthering the anorexic's sense of being "separate" from others. Humans are not fuel tanks; sharing food is one of the basic forms of human bonding. Good relationships are crucial for general well-being, and this might be especially true for recovering anorexics -- that's why, I suspect, family-based treatment for childhood eating disorders is so effective. Overall, while it would be best for everyone to be eating nourishing foods, it's worth thinking about the potential risks and trade-offs in the case of ED patients.

    (Oh, and I'm afraid binging problems are not triggered exclusively by Neolithic food. In my experience, it is just as easy to become "addicted" to Paleo foods that most closely resemble processed, sugary stuff in taste and/or texture -- e.g. fruits, nuts, the "snacky" sort of food. The disordered habits remain the same, but shift to "approved" foods. Although, of course, the intensity of the cravings -- and the damage inflicted on the body -- are on a much lesser scale.)