Here are the American Heart Association's concerns with the study:
• The study is very small, with only 120 total participants and just 60 on the high-fat, low carbohydrate diet.
• This is a short-term study, following participants for just 6 months. There is no evidence provided by this study that the weight loss produced could be maintained long term.
• There is no evidence provided by the study that the diet is effective long term in improving health.
• A high intake of saturated fats over time raises great concern about increased cardiovascular risk – the study did not follow participants long enough to evaluate this.
• This study did not actually compare the Atkins diet with the current AHA dietary recommendations.
"The American Heart Association has dietary guidelines, rather than a rigid diet. These guidelines, revised in 2000, replaced the Step I and Step II diet, which emphasized fat restriction. The current guidelines, based on the best available evidence, emphasize a healthy dietary pattern rich in fruits, vegetables, whole grains, lean meats, fish and poultry, as well as low-fat dairy products," says Robert O. Bonow, M.D., the president of the American Heart Association. "It is important to note that there is no single 'American Heart Association Diet.' Rather there is a set of guidelines designed to be broad enough to accommodate many different food preferences, as well as to provide specific guidance for individuals with specific conditions."
By way of contrast with this small study, a 12-year Harvard study funded by the National Heart, Lung and Blood Institute was also reported at this meeting. This study of 74,000 women showed that those who consumed more fruits and vegetables were 26 percent less likely to become obese than women who ate fewer fruits and vegetables over the same time period. "This is a much more compelling study regarding weight control, because it involved many more individuals over a much longer period," says Bonow.
"Bottom line, the American Heart Association says that people who want to lose weight and keep it off need to make lifestyle changes for the long term – this means regular exercise and a balanced diet," he says. "People should not change their eating patterns based on one very small, short-term study. Instead, we hope that the public will continue to rely on the guidance of organizations such as the American Heart Association which look at all the very best evidence before formulating recommendations."