The National Institutes of Health’s (NIH) “Look AHEAD” trials -- whose major donors included Slimfast, Optifast, and Roche Pharmaceuticals (manufacturers of diet pills Xenical and Alli) -- was touted as the largest lifestyle-intervention study of people living with Type 2 Diabetes. It compared a control group with one that was subjected to strict calorie-restriction, frequent group sessions, physical activity and standard diabetes weight management counseling. The hypothesis was that the group with the intense “lifestyle changes: would have a reduction in negative cardiovascular outcomes. It was cancelled for “futility” because there were no significant differences in cardiovascular outcomes between groups.
Diets don’t work!? That is a huge conclusion that should have been all over the news when this study was cancelled. Were people too scared or making too much money off the diet world to say anything? It took three diet researchers a month to finally make the case in a Huffington Post op-ed.
According to the authors, one of the problems was that they used weight loss as a variable. The participants in the study maintained a 5 percent weight loss for 4 years. This was touted as proof that weight loss interventions were successful since, per the NIH, 5 percent is “an amount of weight loss that experts recommend to improve health.” But that recommendation rests on shaky, shaky ground.
The authors point out that, the “standard is not only remarkably lax but has no medical rationale.” The originals standards were based on the Metropolitan Insurance Tables and were medically arbitrary but aggressive. When they found dieters rarely reached those goals, and they didn’t have any more effective weight loss interventions to try, they simply changed the standard and recommended the same interventions. They just kept changing it until the goal seemed doable -- “despite having no scientifically-supported medical reason for doing so.” Last time I checked, moving the goal post and declaring victory was not a legitimate health strategy.
There was also the problem that it is incredibly rare to maintain any weight loss for 4 years. The authors "analyzed the 20 most rigorous tests of low-calorie, low-fat, or low-carbohydrate diets" and found that the average weight loss maintained by dieters for at least two years didn't even reach two pounds. The study's variable of maintaining weight loss for four years was not realistic at best.
So before you make that New Year’s Resolution to lose weight consider this: Trying to lose weight means that you are doing something that nobody has proven is possible for a reason that nobody has proven is valid. When we follow the evidence (Wei et. al; Matheson et. al; the Cooper Institute Longitudinal Studies etc.) we find that people who engage in healthy habits almost never lose a significant amount of weight, but almost always have better health outcomes (regardless of weight). Choose the healthy lifestyle and not just the arbitrary number. We’ll all be better for it!
