Dieting is Not Very Effective

Confirming what many dieters already know, most diets don’t work all that well over the long term. In a study that just came out today, over 300 moderately obese subjects (average Body Mass Index; 31) were placed on one of three different diets for two years. Participants lost 10-14 pounds within five months, but then they stopped losing weight and even gained some of the weight back over the next year and a half. At the end of a full two years, participants had lost only 6-10 pounds on average – not a lot, considering they were obese to start with.

The study’s authors most likely were disappointed (the study was funded in part by the Atkins Foundation, and a low-carb diet was one of the diets tested.) But based on some observed changes in lipid profiles, they suggest that the diets may have conferred some health benefits to the participants despite the minimal weight loss. It’s an interesting hypothesis, but it’s certainly not a valid conclusion at this point.

Reference: “Weight Loss with a Low-Carbohydrate, Mediterranean, or Low-Fat Diet”, The New England Journal of Medicine 359:229-241, July 17, 2008.