Long-Term Effects of Popular Diets are Unclear
According to many studies, researchers have found that popular commercial diets, such as Weight Watchers and Atkins, are effective in helping people lose weight. However, these studies have mostly examined the short-term effects of dieting. In a new study, researchers concluded that the long-term effects of these diets are very unclear.
"Despite their popularity and important contributions to the multi-million dollar weight loss industry, we still do not know if these diets are effective to help people lose weight and decrease their risk factors for heart disease," said Mark J. Eisenberg, M.D., M.P.H., the study's senior author and Professor of Medicine at Jewish General Hospital/McGill University in Montreal, Quebec, Canada. "With such a small number of trials looking at each diet and their somewhat conflicting results, there is only modest evidence that using these diets is beneficial in the long-term."
For this study, the researchers reviewed clinical trials on four diets, which were Atkins, South Beach, Weight Watchers, and Zone. These diets all claim to help with weight loss and heart health.
The team found that the results from the trials involving the Atkins diet were pretty inconsistent. When the team looked at trials that compared Atkins, Weight Watchers, Zone and usual care, they found that people from all four plans had modest weight loss at one-year. In other trials that compared the effects of Atkins, Weight Watchers and Zone in improving cholesterol, blood pressure, blood sugar levels and other heart risk factors, the researchers did not find any differences between the diets.
In trials that compared the effects of Weight Watchers to usual care, the researchers found that the diet plan helped people lose an average of 7.7 to 13.2 pounds after one year. After two years, however, some of the weight loss was regained.
"A broader lifestyle intervention, which also involves doctors and other health professionals, may be more effective," Eisenberg concluded in the press release. "This also tells doctors that popular diets on their own may not be the solution to help their patients lose weight."
The study was published in the American Heart Association's journal, Circulation: Cardiovascular Quality and Outcomes.