Psychotherapy to treat obesity cannot be another weight loss program. The most popular medical treatments for obesity focus only on weight loss and are no better than the latest fad diet. The clearest message from any unbiased data assessing the weight loss industry is that diets just don't work. Calorie restriction, in whatever proportion of nutrients deemed successful by the latest guru, inevitably leads to a powerful feeling of starvation. Surprisingly, the psychological effects of starvation--obsession with food, strong urges to overeat and slowed metabolism--are a universal reaction from the anorexic to the obese. Although an anorexic patient may have the genetic predisposition to withstand starvation without eating, everyone else will be compelled to eat when ravenous, an evolutionary response clearly geared towards the survival of our species. So the obese person starved for months on a diet can only resist eating for so long and inevitably will eat enough to compensate for the long-term starvation and gain back the lost weight.
A universal reaction to starvation, even in the obese, makes little sense. Shouldn't the body be aware that extra weight has medical consequences? The medical explanation for this conundrum is called the set point theory which postulates that everyone's body has a relatively fluid weight range of about 15% of body weight but will strongly resist moving outside that range. Any pressure to go above or below this range triggers a powerful metabolic response aimed at maintaining the set range. At higher weight, the metabolism increases to burn off extra calories and hunger eases. The opposite occurs at lower weights. The human body has a powerful, innate drive to maintain the status quo.
Based on this theory, the eating disorder treatment community has focused on weight maintenance rather than weight loss. Most anyone who is overweight can lose weight but, once the protective mechanism of set point theory kicks in, no one can keep it off. Built into obesity therapy from the start is a focus on slow, gradual weight loss for a period of a few months followed by a similar period of weight maintenance. In fact, weight maintenance is not only meant to be a critical component of treatment but is necessary for consistent, long-term weight loss. At the end of a weight loss phase, the person will be at or near the bottom of the current set point range. Weight maintenance will allow the set point range to slowly decrease and enable another weight loss phase in the future. It is usually a shock to an adult devoted to the study of dieting to realize that weight loss is only half the battle. All diets promise short-term, rapid weight loss with long-term effects, but all the promises are false. The lure of a diet is rooted in the hope for salvation, for the perfect fix to a lifelong problem. The therapy for obesity immediately grounds the relationship in much slower but realistic prospects of success.
Practically, the treatment involves establishing the calorie and meal goals likely to maintain the patient's weight. For the first 6-12 weeks, the initial weight loss phase, eating 10-15% below the maintenance level should lead to gradual weight loss of 10-15% of body weight. As the patient's weight nears the low end of the range, weight loss slows and then stops, hunger escalates rapidly and metabolism begins to slow and conserve energy. Further dieting invariably triggers excessive hunger, overeating and a profound sense of food deprivation quickly followed by overeating and weight gain. These physiological responses, in a society that idealizes restraint and thinness, become signs of psychological weakness, not the body's adaptation to extreme hunger. Instead, the therapist can identify any sign of increased hunger or deprivation as a sign that the therapy needs to enter the maintenance phase. The addition of the extra food will curtail the excessive hunger quickly and help the body adjust to a new phase of adequate nutrition. After a period of months, the therapy will be ready for a new weight loss phase. At the start of treatment, most patients, after a recent period of overeating, are usually at the top of the set point range, but after a period of weight maintenance, the weight is more towards the middle of the range. Thus, subsequent weight loss phases lead to 5-7% weight loss. Perhaps the hardest aspect of obesity therapy to accept is the length of treatment. The behavior modifications are meant to be lifelong, but the weight loss associated with true weight maintenance takes years, something unheard of in a dieting culture. It typically takes years of overeating to lead to excessive weight gain and it similarly takes time for the body to adjust to weight loss.
From a medical standpoint, this therapy often has long-term success. Several practical issues can disrupt slow and steady progress such as a sedentary lifestyle, diabetes and a chronically slow metabolism from years of excessive dieting. These issues can be addressed with education about the process of obesity treatment and the help of a knowledgeable primary care doctor. However, psychological obstacles also impede the treatment and serve as the most powerful reasons an obese patient gives up. The next few posts will address the pitfalls in obesity therapy and how to overcome them.