The first phase of a caloric restriction study in human subjects found evidence that calorie-restricted diets differing substantially in glycemic load can result in comparable long-term weight loss. In other words, calories matter more than carbohydrates.
The study, at the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University and part of the multi-center Comprehensive Assessment of Long-term Effects of Restricting Intake of Energy (CALERIE) trial, accounted for dietary factors that affect hunger and satiety, used laboratory techniques to measure adherence, and was the first of its kind to provide a complete set of meals and snacks to its participants.