Via Big Fat Blog, a news article about a clinical study (to appear in this month’s Journal of the American Dietetic Association) that directly compares a Health at Every Size (HAES) approach to a Weight Loss Diet approach. I don’t know if this is the first study of this type conducted, but it’s the first one I’ve seen reported on.
Disclaimers: The sample size is pretty small, and the study isn’ t as long as I’d prefer it to be (I think 5 year outcomes are more meaningful than two year outcomes). Nonetheless, the results are striking – and pretty much exactly what Health at Every Size advocates would have predicted.
The UC Davis study was developed to scientifically examine the effectiveness of the Health at Every Size approach compared with traditional dieting. The study started off with 78 female participants ranging in age from 30 to 45 years old. Half were assigned to a dieting group and half to a non-dieting Health at Every Size group.
Members of the dieting group were told to moderately restrict their food consumption, maintain food diaries and monitor their weight. They were provided with information on the benefits of exercise, on behavioral strategies for successful dieting, and on how to count calories and fat content, read food labels and shop for appropriate foods.
Participants in the non-dieting group were instructed to let go of restrictive eating habits associated with dieting. Instead they were counseled to pay close attention to internal body cues indicating when they were truly hungry or full, and to how the food made them feel. They also received standard nutritional information to help them choose healthful foods, and participated in a support group designed to help them better understand how culture influences the experience of obese people and to become more accepting of their larger bodies. In addition, they were encouraged to identify and deal with barriers, including negative self-image, which might get in the way of enjoying physical activity. [...]
Almost all (92 percent) of the non-dieting group stayed in the study throughout the treatment period, while almost half (42 percent) of the dieters dropped out before finishing treatments. This reinforces another message of the research — that in the long run, people are much more likely to stick with a non-diet than a diet.
When the researchers tallied the results from the participants who completed the study, they found that:
- The non-dieters maintained their same weight throughout the study. The dieting group lost 5.2 percent of their initial weight by the end of the 24-week treatment period, but regained almost all of it by the end of the two-year study.
- The non-dieters showed an initial increase in their total cholesterol levels, but this significantly decreased by the end of the study, as did their levels of LDL cholesterol or “bad” cholesterol. The dieters showed no significant change in total or LDL cholesterol levels at any time.
- Both groups significantly lowered their systolic blood pressure during the first 52 weeks of the study. By the end of the study at 104 weeks, however, the non-dieters had sustained this improvement, while the diet group had not.
- By the end of the two-year study, the non-dieters had almost quadrupled their moderate physical activity. The dieting group had a significant increase in physical activity right after the treatment period ended but had slipped back to their initial levels by the end of the study.
- The non-dieters demonstrated significant improvements in self-esteem and depression at the end the study, while the diet group demonstrated a worsening in self-esteem. The dieters’ depression levels initially improved but then returned to baseline.
In summary, while the non-dieters did not lose weight, they succeeded in improving their overall health, as measured by cholesterol levels, blood pressure, physical activity and self-esteem. The dieters, on the other hand, were not able to sustain any of the short-term improvements they experienced and worsened in terms of their self-esteem.
My guess is that this study won’t get much play in the media, but hopefully it’ll lead to future clinical trials of this sort.