Why Does The Food Addiction Model of Obesity Management Lack Good Science?

Yesterday’s guest post on the issue of food addiction (as expected) garnered a lively response from readers who come down on either side of the discussion – those, who vehemently oppose the idea and those, who report success. Fact is, that we can discuss the pros and cons of this till the cows come home, because the simple truth is that the whole notion lacks what my evidence-based colleagues would consider “strong evidence”. Indeed, I did try to find at least one high-quality randomized controlled study on using an addictions approach to obesity vs. “usual” care (or for that matter anything else) and must admit that I came up short. The best evidence I could find comes from a few case series – no controls, one observer, nothing that would compel anyone to believe that this approach has more than anecdotal merit. Yet, the biology (and perhaps even the psychology) of the idea is appealing. Self-proclaimed “food addicts” that I have spoken to readily identify with the addiction model and describe their relationship to “trigger foods” as an uncontrollable factor in their lives that calls for complete abstinence. Animal studies confirm that foods do indeed stimulate the same parts of the brain that are sensitive to other hedonic pleasures and substances. So why the lack of good data? After all, the idea is hardly new – intervention programs for “food addicts” using the 12 steps or other approaches have been around for decades. Can it be simply the lack of academic interest in this issue? I find that hard to imagine – but nothing would surprise me. Is it perhaps because addiction researchers do not take obesity seriously and obesity researchers don’t like the addiction model? I certainly don’t buy the argument that there is no commercial interest in such an approach – if there were strong and irrefutable evidence, I’m sure someone would figure out how to monetize it. So again, I wonder, why the lack of good data? Honestly, I don’t know. I’m open to any views on this (especially if substantiated by actual evidence). @DrSharma Berlin, Germany

Weight Gain With Methadone Treatment For Opioid Addiction

Weight gain is not an uncommon phenomenon with addiction treatment. This has been reported both in smokers and in those with alcohol addiction. Now a study by Jennifer Fenn and colleagues from the University of Vermont report significant weight gain with methadone treatment for opioid addiction in a paper published in the Journal of Substance Abuse Treatment. The retrospective chart review included 96 patients enrolled in an outpatient methadone clinic for ≥ 6 months. Overall mean BMIs increased by about 3 units (from 27.2 to 30.1), which corresponds roughly to an 18 lb or 10% increase in body weight. Interestingly, the weight gain was predominantly seen in women, who gained about 28 lbs or 17.5% body weight compared to men, who only increased their weight by about 12 lbs or 6.4%. As the study did not have access to food records, one can only speculate as to the causes. While better nutrition may well play a role, one could also speculate that there may be some addiction transfer from opioids to calorie-dense foods. Whatever the cause, clinicians should probably be aware of this potential impact of methadone treatment on body weight, as prevention of excess weight gain may be easier than treating obesity once it is established. @DrSharma Edmonton, AB

Does Food Addiction Require Abstinence?

Recently, I had the opportunity of meeting Vera Tarman, a Toronto addiction physician, who is also a self-proclaimed “food addict” and author of the book, “Food Junkies: The Truth About Food Addiction“. It is fair to say that talking to Tarman and reading her book (of which she happily gave me a copy) has definitely given me food for thought. To start with, her book “Food Junkies” is not a typical diet book or even a treatment guide to food addiction. Rather, it is a rather compelling treatise in support of the existence of  a discrete and definable subset of obese (and non-obese) individuals who may well be considered “food addicts” and for whom the only viable treatment is complete abstinence from their respective trigger foods. To put things simply, Tarman (and her co-author Philip Werdell) describes three categories of “eaters” (the following words my attempt at paraphrasing the central ideas as I understand them): Normal Eaters: this is by far the largest group of individuals with obesity, who may overeat for no other reason than that they like food, are surrounded by food, pay little attention to food, let themselves go hungry, have food pushed on them, and/or really don’t obsess or worry about food at all. Normal eaters can learn to control their eating through education and coaching and by changing the circumstances that foster poor willpower: better sleep, stress management, improving social skills, changing their personal food environment, etc. People with Eating Disorders: for this group of individuals, obesity is not the primary problem, rather it is just another symptom of the underlying emotional disturbances that drives their “pathological” eating behaviour. The “spectrum” of these disorders ranges from rather mild “emotional eating” to full blown “binge eating syndrome”. The primary driver of their overeating is psychological (e.g. trauma, grief, abuse, etc.). Once the psychological problem is identified and resolved (or managed, e.g. though cognitive behavioural therapy), they can gain control over their eating behaviour, which in turn can help them control their weight problem. Food Addicts: this group of individuals is literally “addicted” to certain foods (usually foods high in sugar, flour, fat and/or salt) in the same manner that a drug addict would be considered addicted to their drug, with the same clinical signs that range from denial and loss of control, to physical symptoms on “withdrawal” and relapse that can be prompted by minimal exposure, even years after being “clean”… Read More »

Is Food Addiction Better Described As Eating Addiction?

The term “food addiction” has found its way into both the scientific and popular literature. Now, a thoughtful paper by Johannes Hebebrand and colleagues, published in Neuroscience & Biobehavioral Reviews, argues that there is in fact little evidence for addiction to “food” per se (as you would see in addiction to a specific substance) and that therefore, it may be better to describe the addiction-like overconsumption of food as a behavioural addiction, in this case, an addiction to eating. “Eating is intrinsically rewarding and reinforcing, and food consumption is well-known to activate the reward system in the brain; this applies particularly in the physiological state of hunger. It is easy to see that the rewarding properties of food and their activation of the reward pathway might lead intuitively to the idea that food substances may have addictive properties. However, just because eating behavior engages these reward systems, it does not necessarily follow that specific nutrients (substances) are able to evoke a substance addiction. Instead, the complex activation of the reward system as the initial step of the process ending in addiction can be viewed as being dependent on eating (subjectively) palatable foods irrespective of their nutritional/chemical composition.” “Per se, foods are nutritionally complex and there is hardly any evidence to suggest that under normal physiological circumstances humans crave specific foods in order to ingest a specific ‘substance’. Instead, the diet of subjects who overeat typically contains a broad range of different, subjectively palatable foods. It can be argued that access to a diversity of foods, especially a diverse range of palatable foods, may be a pre-requisite for the development of addictive-like eating behavior.” “There is currently no evidence that single nutritional substances can elicit a Substance Use Disorder in humans according to DSM 5 criteria. In light of the lack of clinical studies that have aimed to detect addictions to specific nutrients, it cannot as yet be ruled out that a predisposed subgroup does indeed develop such a substance based addiction, which in theory may be substantially weaker than in the case of addictions based on well-known exogenous substances such as alcohol, cannabis, nicotine or opiates. The fact, that clinical case studies do not abound on an addiction like intake of specific nutrients or even specific foods, would suggest that such cases are rare, if they exist at all. Alternatively, the addiction is so weak that it is not adequately perceived and… Read More »

How Common is Food Addiction?

Although there is little doubt that food addiction exists, the question of how common this may be remains a matter of debate. Now a study by Pardis Pedram and colleagues from Memorial University, Newfoundland, examine this issue in a paper just published in PLoS One. The study looks at 652 adult volunteers (415 women, 237 men) recruited from the general population. ‘Food addiction’ was assessed using the Yale Food Addiction Scale (YFAS), a questionnaire consists of 27 items that assess eating patterns over the past 12 months. The YFAS translates the Diagnostic and Statistical Manual IV TR(DSM-IV TR) substance dependence criteria in relation to eating behaviour (including tolerance and withdrawal symptoms, vulnerability in social activities, difficulties cutting down or controlling use, etc.). The criteria for ‘food addiction’ are met when three or more symptoms are present within the past 12 months together with clinically significant impairment or distress. Based on these criteria, ‘food addiction’ was present in 5.4% of participants (6.7% in females and 3.0% in males) and increased with obesity status. Interestingly enough, the clinical symptom counts of ‘food addiction’ were positively correlated with all body composition measurements across the entire sample (p<0.001) – not just in those with higher BMI. Nevertheless, “food addicts” substantially heavier (11.7 kg), had 4.6 units higher BMI, and had 8.2% more body fat than “non-addicts”. Furthermore, food addicts consumed more calories from fat and protein than controls. Thus, this study shows that as many as 1 in 20 (or 5%) of the general population may have a diagnosis of “food addiction”. Those who do are substantially heavier than individuals who do not meet these criteria. Furthermore, individual symptoms of “food addiction” are associated with higher body weight across the entire range of BMI suggesting that even mild to moderate signs of “addiction” (below the threshold of a formal diagnosis) may contribute to weight gain in the general population. As with all addictions, simply warning about the “evils” or making consumption more difficult (taxing, banning, punishing) is of limited help in addressing the problem. In addition, given that total “food-abstinence” is not an option, the best you can hope for is “harm-reduction” – a rather conservative goal for any addiction. Clearly, not recognising the potential role of food addiction as a contributor to the obesity epidemic means missing the boat on providing appropriate care to individuals with this condition. As with other addictions, “Simply… Read More »