Sunday, March 16, 2008

Health at Every Size

The "Health at Every Size" (HAES) program has attracted a lot of positive attention among fat acceptance groups, and has been touted as an alternative to weight loss programs for obese people. The program was developed by the Association for Size Diversity and Health (ASDAH), a non-profit self-described "international professional organization." I put that phrase in quotes not to be snarky, but because the board of directors is comprised of a mix of people, some of whom have professional training in psychology and nutrition, and some of whom don't, and membership in the organization is open to anyone who is willing to pay for it. The program is based around five basic principles:
  1. Accepting and respecting the diversity of body shapes and sizes
  2. Recognizing that health and well-being are multi-dimensional and that they include physical, social, spiritual, occupational, emotional, and intellectual aspects
  3. Promoting all aspects of health and well-being for people of all sizes
  4. Promoting eating in a manner which balances individual nutritional needs, hunger, satiety, appetite, and pleasure
  5. Promoting individually appropriate, enjoyable, life-enhancing physical activity, rather than exercise that is focused on a goal of weight loss
HAES is a relatively new program, and as a result, the published research about this program per se is still fairly scant. However, there are a few studies of non-dieting psychological interventions in obese patients dating back to the 1990s that likely formed the basis for this program. Ciliska (1) looked at the effects of "education intervention" and "psychoeducational intervention" in obese women (the "education" group had classroom-style lectures about the etiology and health consequences of obesity and the "psychoeducation" group had small discussion group-format meetings about HAES principles). While weight and blood pressure did not change in either of these groups, the psychoeducation group improved in measures of "self-esteem, restraint, and body dissatisfaction." The education intervention group showed no change. Another study (2) looked at the effects of "cognitive treatment" and "behavioural treatment" in obese binge eaters and obese non-binge-eaters. They found that both treatments had statistically significant positive effects on "shape concern, weight concern and eating concern, binge eating, self-esteem, and depression." However, there was little effect on weight loss with those in the behavior treatment group losing 3 kg (6.6 lbs) at the 1 year followup and those in the cognitive treatment group losing 0.3 kg (0.66 lbs). Interestingly, they found that participants who gained weight had equal improvement in their psychological well-being as those who lost weight.

In 2002, Bacon et al. (3) did the first study comparing a HAES-type program to a traditional weight-loss-centered diet program. They looked at subjects they described as "Obese, Caucasian, female, chronic dieters, ages 30-45." These women were divided into two groups, one of which participated in a HAES-type program, with the others following a traditional diet program. Both groups received 6 months of weekly group intervention followed by 6 months of monthly after-care group support. After this year, they found that both groups had demonstrated significant improvements in metabolic fitness, psychological variables and eating behaviors. While they reported that attrition was high in the diet group (41%) compared to the HAES group (8%), the diet group showed significant weight loss (5.8 kg or 13 pounds) the HAES group did not. The authors concluded from this that the main advantage of HAES over traditional dieting is the lack of attrition.

In 2005 Bacon's group at Davis published another study, the first one to actually use the term "Health at Every Size" (4). While this study was very similar in methodology to the first one they had published, the results were quite different. While the HAES group did not show any significant change in weight throughout the study period, members of the diet group lost an average of 5.8 kg in the initial six months, however, in the six month followup period they gained back some of that weight, and they found the net change in weight (3.2 kg, or 7 pounds) to be statistically insignificant. They found that the HAES group improved their total cholesterol, HDL, LDL and systolic blood pressure scores, whereas the diet group did not. They also found that the HAES group had significant long-term improvement (this was measured 2 years out) in a number of measures of psychological well being and eating disordered behavior, whereas the diet group showed long-term improvement in only a couple of these measures.

So how should these conflicting findings be interpreted? The papers by Bacon's group at UC Davis seem particularly confusing, as their two studies were carried out under very similar conditions but had quite different results. This may have been a result of their small sample size (after attrition, there were only 19 women left in the diet group in their second study). It also may have been a result of demographic differences between the two groups in that second study. While the authors do not mention this explicitly, a table in the paper shows that in the HAES group, 89.5% of women were married or in a domestic partnership, whereas only 68% of the women in the diet group were in such relationships. The two groups also differed in their education levels: 53% of the HAES group were college graduates, whereas 63% of the diet group were. These disparities may have resulted from the attrition in the diet group, but they are probably an important factor to consider in assessing the results of this study.

Another problem with studying interventions like HAES counseling is that it is subject to significant observer bias. If you are studying, say, a drug, you can do a double-blind study where both the doctors who are scoring the outcomes of the study and the subjects themselves are unaware whether they are being treated with the drug in question or a placebo. If you are comparing two types of counseling that is obviously not possible. In these studies, it is possible that the HAES counselors were simply better or more enthusiastic than the counselors leading the control groups.

Clearly, many questions remain about HAES. A few things do seem to be consistent from study to study, though. There seems to be reasonable evidence that HAES improves self-esteem. Its effects on weight loss, binge eating, and other physical measures are less clear.

1. Ciliska D. Evaluation of two nondieting interventions for obese women. Western Journal of Nursing Research 20: 119-135, 1998.

2. Nauta H, Hospers H, Jansen A. One-year follow-up effects of two obesity treatments on psychological well-being and weight. British Journal of Health Psychology 6: 271-284, 2001.

3. Bacon L, Keim NL, Van Loan MD, Derricote M, Gale B, Kazaks A, Stern JS. Evaluating a "non-diet" wellness intervention for improvement of metabolic fitness, psychological well-being and eating and activity behaviors. International Journal of Obesity and Related Metabolic Disorders, 26: 854-865, 2002.

4. Bacon L, Stern JS, Van Loan MD, Keim NL. Size Acceptance and Intuitive Eating Improve Health for Obese, Female Chronic Dieters. Journal of the American Dietetic Association 105: 929-936, 2005.

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