The study centered on 270 men and women who were randomly assigned to a low-carbohydrate diet or a low-fat diet for two years. Those on the low-carb diet were told to limit carbohydrates and eat foods high in fat and protein. Those on the low-fat diet cut back on calories and fat and limited protein to about 15% of calories from protein, 30% from fat and 55% from carbohydrate.
Foods such as jelly that are high in sugar were discouraged on the low-carb diet, and high-carb foods such as bagels were banned on the low-carb diet.
Researchers surveyed participants about how often they craved sweets, high-fat foods, carbohydrates and starches and fast-food fats. Participants also were asked about their preferences for certain foods -- this was used to measure how much they liked the foods that were restricted from their diets.
The researchers found that those in the low-carbohydrate group had much larger drops in cravings for carbs and starches compared to the low-fat group. The low-carb group showed substantially bigger declines in preferences for high-carb and high-sugar foods compared to the low-fat group. The low-carb group also was less bothered by hunger than those in the low-fat group.
The low-fat group, meanwhile, saw bigger decreases in cravings for high-fat foods than did the low-carb group. The low-fat group also had larger reductions in preferences for low-carb/high-protein foods compared to the low-carb group.
The findings "demonstrate that promoting the restriction of specific types of foods while dieting causes decreased cravings and preferences for the foods that are targeted for restriction," the authors wrote.
That's counterintuitive to what most people think they'll experience when they diet and, the authors noted, could put those dieters' concerns to rest.
Obesity, April 2011.