This New York Times article, What Really Makes Us Fat, discusses the result of a study that produced surprising results.
The experiment: Three separate groups on three different diets stuck to a diet for a month. All subjects consumed the same amount of calories.
Diet 1: A high-carbohydrate low-fat diet - fruits, vegetables, whole grains, lean sources of protein.
Diet 2: A low glycemic index diet - fewer carbohydrates in total - non-starchy vegetables, beans, and minimally processed sources.
Diet 3: The Atkins diet - high in fat and protein and very low in carbohydrates.
Results: The fewer carbohydrates consumed, the more energy was expended.
A quote from the article:
“On the very low-carbohydrate diet, subjects expended 300 more calories a day than they did on the low-fat diet and 150 calories more than on the low-glycemic-index diet.”