COVERT MANIPULATION OF THE RATIO OF DIETARY-FAT TO CARBOHYDRATE AND ENERGY DENSITY - EFFECT ON FOOD-INTAKE AND ENERGY-BALANCE IN FREE-LIVING MEN EATING AD-LIBITUM

We previously increased the energy density and fat content across thre e diets (factorial design), which led to a marked increase in energy i ntake in six men over 7 d while continuously resident in a whole-body indirect calorimeter. In the present study we fed the same diets to se ven men who were resident in, but not confined to, a metabolic suite f or 2 wk/diet. This added a component of increased physical activity. T he fat, carbohydrate, and protein contents, respectively, of each diet (as a percent of energy) were as follows: low-fat (LF), 20:67:13; med ium-fat (MF), 40:47:13; and high-fat (HF), 60:27:13; Energy density in creased as the percent of fat in the diet increased. Energy intakes fr om the LF, MF, and HF diets (9.11, 10.32, and 12.78 MJ/d, respectively ) were almost identical to those in our calorimeter study (9.02, 10.2, and 12.35 MJ/d, respectively) whereas energy expenditures (estimated by the doubly labeled water method) were 12.45, 12.10, and 11.97 MJ/d on the LF, MF, and HF diets, respectively, compared with 9.48, 9.53, a nd 9.78 MJ/d, respectively, in our calorimeter study. This finding sug gests that diet composition and energy expenditure combined influence energy balance in humans.