Study reveal that of the 32 major commercial weight-loss programs marketed in the US, only 11 have been rigorously studied in randomized controlled trials.
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Researchers at Johns Hopkins reviewed 4,200 studies for solid evidence of their effectiveness in the long-term. They found that of the 32 major commercial weight-loss programs marketed nationwide, only 11 have been rigorously studied in randomized controlled trials. The investigators also found that from these studies, only two programs, Jenny Craig and Weight Watchers, are supported by gold-standard data showing that participants, on average, lost more weight after one year in these programs than people who were either dieting on their own, got printed health information, or received other forms of education and counseling sessions.
Participants in the very-low-calorie meal replacement programs were seen to have lost more weight than nonparticipants in trials lasting from four to six months. However, the authors found only one long-term study, which showed no benefit from such a program at 12 months. The researchers noted that very-low-calorie programs also carry higher risks of complications, such as gallstones.
The study authors said, "Results in those programs were generally modest, with participants losing on average between 3 and 5% more than the studies’ control groups of non-program participants. NutriSystem also produced more weight loss at three months than counseling or education alone, but we were unable to find any long-term trials of that program. Programs based on the Atkins diet, high in fat, low in carbohydrates, also helped people lose more weight at six months and 12 months than counseling alone. The approach appears promising. No definite conclusions could be made about Slim-Fast and the Internet-based programs."
The study appears in the Annals of Internal Medicine.
Source-Medindia