Low-carb diets no quick fix: study
Tue Apr 8,11:04 AM ET Add U.S. National - AFP to My Yahoo!



CHICAGO (AFP) - Diets low in carbohydrates have got some good press in recent months, but a study suggests they are no better than conventional calorie-counting regimes.



"While these diets are effective in the short term, weight loss results from reduced calories, not carbohydrate restriction," said Dena Bravata, a lead researcher on the paper which is published in this week's edition of the Journal of the American Medical Association (news - web sites).


Advocates of low-carb, high-protein diets have long claimed that these regimes promote rapid weight-loss because they force the body to metabolise fat stores for energy instead of carbohydrates.


Cardiologist Robert Atkins, perhaps the best-known advocate of the philosophy, has sold millions of books promoting just this advice.


But medical professionals, including the American Dietetic Association and the American Heart Association (news - web sites), have cautioned the public against these weight-loss programs, warning that they could potentially lead to kidney and liver problems because of their high fat content.


In an effort to establish what the science showed about the success of these diets, researchers from Stanford University Medical Center and Yale University reviewed 107 studies on low-carb diets carried out since the mid-1960s up to the present day.


Their analysis showed that people on diets of 60 or fewer grams of carbohydrates a day did lose some weight, but the lost pounds were due to a restricted calorie intake and the length of the diet.


"The greatest predictors of weight loss appear to be caloric intake and diet duration," said Bravata, a social science researcher at Stanford.


"The findings suggest that if you want to lose weight, you should eat fewer calories and do so over a longer period of time."


The researchers could find no evidence that the diets adversely affected the cholesterol, glucose, insulin and blood-pressure levels of the volunteers who took part in the studies (some 3,268 people) but said more research was needed to thoroughly evaluate any side effects.


In an editorial accompanying the study, George Bray, an obesity expert at Louisiana State University in Baton Rouge, suggested that the popularity of low-carb regimes might reflect dieters' preferences.


"The broader issue of whether a unique diet exists that will produce long-term weight loss has yet to be evaluated. Although the truth of "a calorie is a calorie" has been reaffirmed by the systematic review by Bravata et al, the question of whether patients can adhere more easily to one type of diet or another remains to be answered."