Weight-loss outcomes similar among named diet programs

Any low-carbohydrate or low-fat diet was associated with the largest amounts of weight loss, according to recent study findings published in JAMA.

Researchers also recommend that people choose a weight-loss program that they will follow.

Bradley C. Johnston, PhD, of The Hospital for Sick Children Research Institute, and colleagues conducted a meta-analysis of 59 articles reporting 48 randomized clinical trials (7,286 individuals; mean age, 46 years; median weight, 207.5 lb) to determine the effectiveness of popular branded diets on weight loss.

Bradley C. Johnston

Six-month follow-up was conducted for 43 trials, and 25 trials had 12-month follow-up.

At 6-month follow-up, compared with no diet, all diets were superior. There was a mean difference in weight loss of 19.2 lb for low-carbohydrate diets and a mean difference in weight loss of 17.6 lb for low-fat diets vs. no diet.

At 12-month follow-up, average weight loss was 2.2 lb to 4.4 lb less than that of the 6-month follow-up. Low-carbohydrate and low-fat diets continued to show the greatest effects at 12-month follow-up.

“Our findings should be reassuring to clinicians and the public that there is no need for a one-size-fits-all approach to dieting because many different diets appear to offer considerable weight loss benefits,” the researchers wrote. “This is important because many patients have difficulties adhering to strict diets that may be particularly associated with cravings or be culturally challenging (such as low-carbohydrate diets). Our findings suggest that patients may choose the diet that gives them the least challenges with adherence. Although our study did not examine switching between diets, such a strategy may offer patients greater choices as they attempt to adhere to diet and lifestyle changes.”

In an accompanying editorial, Linda Van Horn, PhD, RD, of the department of preventive medicine at the Northwestern University Feinberg School of Medicine, wrote that the study findings “underscore the importance of effective diet and lifestyle interventions that promote behavioral changes to support adherence to a calorie-restricted, nutrient-dense diet that ultimately accomplishes weight loss.

“Choosing the best diet suited to an individual’s food preferences may help foster adherence, but beyond weight loss, diet quality including micronutrient composition may further benefit longevity,” she wrote.

For more information:

Johnston BC. JAMA. 2014;doi:10.1001/jama.2014.10397.

Van Horn L. JAMA. 2014;doi:10.1001/jama.2014.10837.

Disclosure: The study was funded in part by a Canadian Institute of Health research knowledge synthesis grant via the Public Health Agency of Canada. One researcher reports holding a Canadian Institute of Health Research new investigator award and another reported holding a Canada Research Chair in global health.