Gary D. Foster

Obesity: Responding to the Global Epidemic

Obesity has reached epidemic proportions in the United States and other developed nations. In the United States, 27% of adults are obese and an additional 34% are overweight. Research in the past decade has shown that genetic influences clearly predispose some individuals to obesity. The marked increase in prevalence, however, appears to be attributable to a toxic environment that implicitly discourages physical activity while explicitly encouraging the consumption of supersized portions of high-fat, high-sugar foods. Management of the obesity epidemic will require a two-pronged approach. First, better treatments, including behavioral, pharmacologic, and surgical interventions, are needed for individuals who are already obese. The second and potentially more promising approach is to prevent the development of obesity by tackling the toxic environment. This will require bold public policy initiatives such as regulating food advertising directed at children. The authors call not for the adoption of a specific policy initiative, but instead propose that policy research, based on viewing obesity as a public health problem, become a central focus of research.

What is a reasonable weight loss? Patients' expectations and evaluations of obesity treatment outcomes.

Expert panels and governmental guidelines now recommend that obese persons seek modest (i.e., reasonable) reductions in body weight rather than striving for ideal weights. Little is known, however, about patients views of what is a reasonable weight loss. This study assessed patients goals, expectations, and evaluations of various outcomes before, during, and after 48 weeks of treatment. Before treatment, 60 obese women (99.1 +/- 12.3 kg; body mass index of 36.3 +/- 4.3 kg/ m2) defined their goal weight and 4 other weights: dream weight; happy weight; acceptable weight; and disappointed weight. Goal weight averaged a 32% reduction in body weight. A 17-kg weight loss was defined as disappointed; a 25-kg loss, was acceptable. After 48 weeks of treatment and a 16-kg weight loss, 47% of patients did not achieve even a disappointed weight. These data illustrate the dramatic disparity between patients expectations and professional recommendations and the need to help patients accept more modest weight loss outcomes.

Obesity and quality of life

The focus of this review is the impact of obesity and weight loss on quality of life. A focus on quality of life broadens the scope of treatment efficacy beyond weight loss and provides a patient-centered perspective. The concept of quality of life is defined, and both general and obesity-specific measures are reviewed. It is clear that obesity confers negative consequences on both the physical and psychosocial aspects of quality of life, especially among the severely obese. The effects of weight loss appear to be favorable, although few studies have examined non-surgical interventions. Future studies would be enhanced by assessing a variety of approaches to weight loss by using both general and obesity-specific measures of quality of life and conducting follow-up studies to assess the effects of weight regain on quality of life.

Exercise in the Treatment of Obesity Effects of Four Interventions on Body Composition, Resting Energy Expenditure, Appetite, and Mood

This study investigated changes in body composition, resting energy expenditure (REE), appetite, and mood in 128 obese women who were randomly assigned to 1 of 4 treatment conditions: diet alone, diet plus aerobic training, diet plus strength training, or diet combined with aerobic and strength training (i.e., combined training). All women received the same 48-week group behavioral program and were prescribed the same diet. Exercising participants were provided 3 supervised exercise sessions per week for the first 28 weeks and 2 sessions weekly thereafter. Participants across the 4 conditions achieved a mean weight loss of 16.5 +/- 6.8 kg at Week 24, which decreased to 15.1 +/- 8.4 kg at Week 48. There were no significant differences among conditions at any time in changes in weight or body composition. Women who received aerobic training displayed significantly smaller reductions in REE at Week 24 than did those who received strength training. There were no other significant differences among conditions at any time on this variable or in changes in appetite and mood.

PSYCHOSOCIAL ASPECTS OF OBESITY AND OBESITY SURGERY

There is a growing consensus that bariatric surgery is the treatment of choice for extremely obese individuals who have failed to reduce their weight satisfactorily using behavioral or pharmacologic interventions. The gastric bypass in particular is associated with excellent long-term weight loss. Although most extremely obese individuals will have essentially normal psychological functioning, a significant minority suffer from depression, binge eating, trauma, or other emotional complications that may require treatment before or after bariatric surgery. A structured behavioral assessment, conducted by a mental-health professional and a registered dietitian, can readily identify those who are most likely to require adjunct counseling.

Behavioral treatment of obesity

The behavioral treatment of obesity consists of a set of principles and techniques to help overweight individuals modify inappropriate eating and activity habits. As provided in University and hospital clinics, this approach produces an average loss of 8.5 kg (9% of initial weight) in approximately 20 weeks. The maintenance of weight loss is facilitated by the provision of long-term patient-provider contact as well as by the use of weight-loss medications. The most promising results are likely to be obtained when behavioral and pharmacologic approaches are combined. The article concludes with a discussion of the importance of treating obese individuals with respect and compassion.

Body image in obese women before, during, and after weight loss treatment.

Body image, as measured by the Appearance Evaluation and Body Areas Satisfaction scales of the Multidimensional Body-Self Relations Questionnaire (T.F. Cash, 1994b), was assessed in 59 obese women before, during, and after 48 weeks of weight loss treatment. Before treatment, positive ratings of body image were associated with higher levels of self-esteem, lower levels of dysphoria, and fewer previous diets. After 24 weeks and a mean weight loss of 19.4 kg (SD = 6.5), participants showed significant (p < .0001) improvements in body image. A small weight gain from Week 24 to Week 48 was associated with a slight but significant worsening in both measures of body image. Nevertheless, after 48 weeks and a mean weight loss of 16.3 kg (SD = 7.1), body image was significantly improved from baseline (p < .0001). Changes in body image were not related to changes in weight. Future studies are needed to separate the effects of treatment and weight loss on body image in obese persons.

Behavioral treatment of obese binge eaters: do they need different care?

This study investigated the relationship between binge eating and the outcome of weight loss treatment. Participants in a 48-week trial of a structured diet combined with exercise and behavior therapy were classified into one of four groups: no overeating; episodic overeating; subthreshold binge-eating disorder(BED); and BED. Binge eating status was not associated with either dropout or adherence to the diet, but did affect weight loss and mood. The BED group lost significantly more weight at the end of treatment than all other groups, even when adjusting for initial weight. At 1-year follow-up, there were no differences among groups in weight loss or weight regain. The BED group began treatment with significantly higher BDI scores, but improvement in mood occurred by week 5. On the basis of these findings, and a review of the recent literature, we conclude that obese binge eaters respond as favorably to standard dietary and behavioral treatments as do obese nonbingers.

Great expectations: "I'm losing 25% of my weight no matter what you say".

This study investigated whether informing obese individuals that they would lose only modest amounts of weight would lead them to adopt more realistic weight loss expectations. At a screening interview, 53 obese women reported that they expected to lose the equivalent of 28% of their initial weight during 1 year of treatment with the medication sibutramine. Prior to beginning treatment, participants were informed, both verbally and in writing, that they could expect to lose 5% to 15% of initial weight, the loss typically induced by current behavioral and pharmacologic approaches. This information, however, had little impact on their weight loss expectations when assessed on subsequent occasions. Results are discussed in terms of the origins, clinical significance, and potential malleability of obese individuals weight loss expectations.

Relationship of dieting history to resting metabolic rate, body composition, eating behavior, and subsequent weight loss.

This study examined the relationship of dieting history to resting metabolic rate, body composition, and subsequent weight loss in 50 obese women. A preliminary study showed that the women were able to report with satisfactory reliability the number of diets in which they had engaged (mean = 4.9 +/- 0.5), as well as the total weight loss resulting from these diets (mean = 55.9 +/- 6.0 kg). We found no evidence that weight cycling, as measured by either of these variables, was associated at baseline with a reduced resting metabolic rate or an increased percentage of body fat. Nor did we find that weight cycling was associated with smaller weight losses in a prospective trial in which subjects were treated by very-low-calorie diet and behavior therapy. The clinical implications of these findings are discussed, as are the methodological problems encountered in conducting research on this topic.