CHICAGO — A study published this week in the Journal of the American Medical Association indicated low-carbohydrate dieters over the course of a single year lost more weight than subjects on other popular diets but appeared by the end of the study to be on track to regain their lost weight. The research also supported the idea that diets in general do not work.
The study, conducted by researchers associated with Stanford Prevention Research Center and the Department of Medicine at Stanford University Medical School, did not find evidence of adverse health consequences over the course of one year on an Atkins diet.
Conducted between February 2003 and October 2005, the study placed 311 overweight/obese women on one of four diets — Atkins, Zone (Barry Sears), Ornish (low fat) or LEARN (based on the U.S. Dietary Guidelines for Americans).
Subjects on the Atkins diet at 12 months lost an average of 10 lbs; LEARN, 6 lbs; Ornish, 5 lbs; and Zone, 3 lbs.
The ultimate issue identified by the authors was not diets.
"The ongoing obesity epidemic, along with its health costs and consequences and the health benefits of weight loss have been well established," they said.
Against this measure, none of the diets was successful. With an average starting weight of roughly 189 lbs, the average woman on each of the dieting regimens remained overweight when the study concluded.
While noting "concerns about adverse metabolic effects of the Atkins diet were not substantiated," the authors suggested physicians should be comfortable allowing their patients to follow the Atkins diet. Still, they noted there is good reason to be skeptical of its prospects for long-term success.
"Weight-loss trajectories for each group had not stabilized at 12 months," they said. "The trajectories of weight change between 6 and 12 months suggest that longer follow-up would likely have resulted in progressively diminished group differences. "
Compliance questions also stand out in the study, the authors noted.
"Other limitations included the lack of a valid and comparable assessment of individual adherence to the four different diets, the lack of data on whether participants had familiarity using any of the specific study diets prior to enrolling in the trial and the lack of assessment of satiety," they said.
The Grain Foods Foundation said initial press reports in reaction to the study did not offer a universal vindication of Atkins dieting.
To the contrary, the foundation, which has a "rapid response" function when major news stories related to grain-based foods are released, said "clinicians (including the study authors) are saying the results don’t point to Atkins as a long-term weight loss solution since the study’s timeframe isn’t long enough to be conclusive."