A concept frequently mentioned in diet books is the upgraded calorie burn you get after eating certain types of meals, a.k.a. the thermic effect of food. The type of diet considered most amenable to the greater thermic effect is higher in protein. Researchers from the University of Arizona decided to test the theory to see if had any merit.
Eleven young women ate either a high-carbohydrate diet (60 percent carbs, 15 percent protein and 25 percent fat) or a high-protein diet (40 percent carbs, 30 percent protein and 30 percent fat). Observant readers will recognize the latter diet as having the precise nutrient composition of the popular Zone diet espoused by biochemist Barry Sears. For two days before testing, the women all ate the high-carb diet. On the testing day they reported to the lab in a fasting state, and their resting metabolic rates were measured.
The subjects remained at the lab the entire day and were randomly assigned to either the high-carb or high-protein diet in three meals spaced at four-hour intervals over a 12-hour period. All the meals were measured precisely. The subjects were inactive, and their resting metabolic rates were measured 2 1/2 hours following each meal and also after they lay down for 30 minutes. The entire procedure was repeated after a month using an alternative diet’high-carb eaters ate the high-protein diet and vice versa.
The results showed that consuming a high-protein diet led to a significantly higher TEF compared to a higher-carb diet, meaning that you burn more calories following a high-protein meal than a high-carbohydrate meal. IM