Weight loss comparable among 'named' diets.
All the "named" dietary programs are likely to yield the same 6-kg weight loss at 1 year, so patients should be encouraged to follow whichever one they are most likely to adhere to, according to a report.
Despite advertising claims that certain named diets are superior to others, there have been very few head-to-head comparison studies, and none have had adequate numbers to achieve a definitive conclusion, said Bradley C. Johnston, Ph.D., of the Hospital for Sick Children Research Institute, Toronto, and his associates.
The investigators performed a network meta-analysis that included all available data from 48 randomized clinical trials (7,286 participants) to estimate the relative effects of three low-carbohydrate diets (Atkins, South Beach, and Zone), two low-fat diets (Ornish and Rosemary Conley), and five moderate-macronutrient diets (Biggest Loser, Jenny Craig, Nutrisystem, Volumetries, and Weight Watchers). "We included dietary programs with recommendations for daily macronutrient, caloric intake, or both for a defined period (12 weeks or longer), with or without exercise (e.g., jogging, strength training) or behavioral support (e.g., counseling, group support)," they said.
All the diets were superior to no diet and all showed an approximate 8-kg weight loss at 6 months with a regain of approximately 2 kg at 12 months, Dr. Johnston and his associates said (JAMA 2014 Sept. 2 [doi: 10.1001/jama.2014.10397]).
Only 5 of the 48 trials reported on adverse events, and only 1 of them directly compared adverse events between low-carbohydrate against low-fat diets. That study found all adverse events to be more common with low-carbohydrate diets, including constipation (68% vs 35%), headache (60% vs 40%), halitosis (38% vs 8%), muscle cramps (35% vs 7%), diarrhea (23% vs 7%), general weakness (25% vs 8%), and rash (13% vs 0%).
This study was supported by the Canadian Institute of Health. Dr. Johnston and his associates reported no financial conflicts of interest.
Caption: The dietary programs were likely to yield the same 6-kg weight loss at 1 year.
Please note: Illustration(s) are not available due to copyright restrictions.
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|Author:||Moon, Mary Ann|
|Publication:||Family Practice News|
|Date:||Sep 15, 2014|
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