Successful Weight Loss
Posted by dlende on April 5, 2008
Is successful weight loss possible? Beginning from the presumption of “will power,” no. People who “diet” generally lose and gain weight in a yo-yo fashion, often with greater rebounds. But some people do successfully lose weight and maintain that loss. What makes them different, and what lessons does that hold for thinking about weight loss?
Let us start with this 2005 article by leading researcher Rena Wing and Suzanne Phelan. Here’s the abstract:
There is a general perception that almost no one succeeds in long-term maintenance of weight loss. However, research has shown that 20% of overweight individuals are successful at long-term weight loss when defined as losing at least 10% of initial body weight and maintaining the loss for at least 1 y. The National Weight Control Registry provides information about the strategies used by successful weight loss maintainers to achieve and maintain long-term weight loss. National Weight Control Registry members have lost an average of 33 kg and maintained the loss for more than 5 y. To maintain their weight loss, members report engaging in high levels of physical activity (1 h/d), eating a low-calorie, low-fat diet, eating breakfast regularly, self-monitoring weight, and maintaining a consistent eating pattern across weekdays and weekends. Moreover, weight loss maintenance may get easier over time; after individuals have successfully maintained their weight loss for 2–5 y, the chance of longer-term success greatly increases. Continued adherence to diet and exercise strategies, low levels of depression and disinhibition, and medical triggers for weight loss are also associated with long-term success. National Weight Control Registry members provide evidence that long-term weight loss maintenance is possible and help identify the specific approaches associated with long-term success.
A 2001 review article by Rena Wing and James Hill makes their argument more explicit: “common behavioral strategies, including eating a diet low in fat, frequent self-monitoring of body weight and food intake, and high levels of regular physical activity.”
And a 2005 review by Elfhad and Rossner expands on this point:
Successful weight maintenance is associated with more initial weight loss, reaching a self-determined goal weight, having a physically active lifestyle, a regular meal rhythm including breakfast and healthier eating, control of over-eating and self-monitoring of behaviours. Weight maintenance is further associated with an internal motivation to lose weight, social support, better coping strategies and ability to handle life stress, self-efficacy, autonomy, assuming responsibility in life, and overall more psychological strength and stability. Factors that may pose a risk for weight regain include a history of weight cycling, disinhibited eating, binge eating, more hunger, eating in response to negative emotions and stress, and more passive reactions to problems.
However, the problem is that this behavioral approach identifies behavior as emerging from the individual alone. It returns to the implicit assumption of “willpower”. Here’s a quote from one article: “exercise-related motivational factors, with a special emphasis on intrinsic sources of motivation (e.g., interest and enjoyment in exercise), play a more important role in longer term weight management.” Motivation as intrinsic…
Or another quote, “We propose that the modern environment has taken body weight control from an instinctual (unconscious) process to one that requires substantial cognitive effort. In the current environment, people who are not devoting substantial conscious effort to managing body weight are probably gaining weight… In order to combat the growing epidemic we should focus our efforts on providing the knowledge, cognitive skills and incentives for controlling body weight.” So, we need to prop up “will power” with knowledge and skill…
It is into this background assumption that diet plans fall, whether academic ones like the LEARN program described by Gina Kolata in Rethinking Thin (Lifestyle, Exercise, Attitudes, Relationships, Nutrition) or the, say, Atkins Diet, with its focus on prescriptions and a pseudo-explanation (carbohydrates make you fat). The prevailing approach is that there is some set of techniques that the individual can simply follow, and presto, successful weight loss. And if it gets difficult, try harder. That’s where willpower comes in.
Let us set that against the reality of a prospective study which points that weight control strategies actually predict weight gain among girls in adolescence. Eric Stice and colleagues found that “Self-reported dietary restraint, radical weight-control behaviors, depressive symptoms, and perceived parental obesity—but not high-fat food consumption, binge eating, or exercise frequency—predicted obesity onset… The fact that self-reported, weight-control behaviors identified girls at risk for obesity implies that high-risk youths are not engaging in effective weight-control methods.”
So “willpower” is not the answer, at least conceived as an intrinsic and internal property of the individual (see Greg’s post, Tightening Your Belt on Your Mind).
For me, the key is recognizing that the research is probably right—behavior matters. But what’s wrong is assuming that behavior is a property of internal dynamics of the person, whether that is a set of cognitive skills, the exercise of willpower, or genetic vulnerabilities. This approach avoids basics facts about culture. We are built to respond, instinctually, to culture. Culture naturalizes things, which from the brain side means that our brains do lots of “cultural” things without conscious awareness and control. Finally, culture bundles things together, combining disparate elements into overarching patterns that significantly shape behavior.
Thus, our behavior takes place within specific contexts, relationships, and symbolic meanings. It is also linked to subjective experience, available opportunities, bodily function, and the ongoing interpretation of our memories.
Though not put in these terms, I see this as the basic point of this Brug et al. (2005) article:
Many of the commonly-used theories provide at best information on what needs to be changed to promote healthy behavior, but not on how changes can be induced… For more effective interventions, behavior change theory needs to be further developed in stronger research designs and such change-theory should especially focus on how to promote action rather than mere motivation. Since voluntary behavior change requires motivation, ability as well as the opportunity to change, further development of behavior change theory should incorporate environmental change strategies.
This view contrasts greatly with the present equation of “self,” say “cognitive skills” or “intrinsic motivation,” and some imagined set of diet recommendations, popular or scientific, at the heart of current plans. In essence, we are selling ourselves a huge placebo effect, the belief that “we can do something.” But in this case the placebo effect is to make us feel better, make us feel we can do something, rather than overturning cherished assumptions and figuring out what will work and what will not.
So let us turn to what we know about weight gain and weight loss. Conscious efforts to control food intake followed by failure tend to set up excessive ways of eating. Obesity is linked to social networks. Exercise or high levels of activity help, with exercise shaped by relationships, work structure, contextual opportunity, early habits, and so forth. Depression does not help. Eating for comfort or other emotional reasons heightens the risk of excessive eating (that “disinhibited style”). Subjective experience of hunger matters, as does mindless eating, and these are linked to the reasons we eat, the contexts where we eat, the people with whom we eat, and so forth. In other words, it’s complicated, but not endlessly complicated.
I believe that successful weight loss involves changing the three interacting systems I set out in the post On the Causes of Obesity : (1) a body-brain system that regulates energy expenditure and storage; (2) an appetite system, largely mediated by the brain but with direct influences from the body and environment; and (3) a cultural biology system, mediating things like eating patterns, body image, and expected exercise.
“Willpower” won’t induce the sorts of systemic changes to canalize all those systems in favor of weight loss and continued lower-weight maintenance. But as individual change matches with shifting social relationships, changed contexts, the reinterpretation of meanings, and the experience of inequality, then successful weight loss is much more likely. Simply put, people change when it matters to them and matters to their environment in a deep, embodied sense. Biology, person, and culture need to all “get along.”
But we live in an environment that has fast-food chains pushing their food (profit matters), that has significant inequality, that supports the use of high-fructose corn syrup in mass food production both politically and financially, that builds environments aimed at limiting physical movement, that places biomedicine (e.g., surgery and drugs) at the center of solving obesity, and a host of other factors that encourage a perfect storm. How bad that storm is is a matter of debate, but even 100,000 extra deaths a year still sounds pretty terrible to me.
We also live in a social environment where change strategies are, for the most part, either focused on the individual (e.g., cognitive skills) or on rational policy (e.g., provide better information about the risks). Thus, our approach to making a difference does little to address the canalization of weight (in either direction) or the socioeconomic environments that can help push canalization.