In the constant battle of the diets, the longest head-to-head study of popular weight loss plans has claimed Atkins the winner against the Ornish diet, the Zone, and even U.S. guidelines; however, experts agree that the biggest lesson is how difficult it is to lose weight and keep it off.
The study involved 311 women averaging 40 years in age and starting with and average weight of 189 pounds. The purpose was to gauge the effectiveness of using a diet book to lose weight. The women were randomly assigned to read one of four diet books, attended weekly classes that addressed diet questions for eight weeks, and were then mostly on their own for the remaining 10 months.
Overweight women on the low-carb, high-fat Atkins diet lost more weight and had slightly lower blood pressure and higher levels of HDL cholesterol (the good kind) than those on the low-carb Zone diet, the very low-fat, high-carb Ornish diet, and a low-fat, high-carb diet recommended by U.S. guidelines.
On average, Atkins followers lost 10 pounds in 12 months. In comparison, those following national guidelines lost almost 6, Ornish dieters lost almost 5, and Zone dieters lost an average of 3.5 pounds. Scientifically, however, these results from 12 months of dieting are not different enough to rule out the possibility of chance being a strong factor.
Stanford University researcher Christopher Gardner, the lead author of the study, said the results show that Atkins may be healthier than critics argue. At the same time, Gardner made sure to explain that the results did not bring dramatic weight loss, and that Atkins “isn’t the solution for the obesity problem.”
The dieters lost most of their weight in the early stages of their diet, an average of 13 pounds for Atkins followers, which was nearly double the closest competitor, U.S. guidelines. After the first stages, however, most dieters regained weight, most noticeably Atkins women. By the end, most of the women were not following any of the diets very strictly, although Atkins dieters were the most loyal.
And with an average starting weight of 189 pounds, even maintaining a 13-pound weight loss keeps these dieters at an overweight level.
Yale University food policy researcher Kelly Brownwell, whose book promotes diet and lifestyle changes similar to U.S. guidelines, said, “the study shows that nothing works very well… it just screams out for the need to prevent obesity.”