title: 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.
abstract: We previously increased the energy density and fat content across three diets (factorial design), which led to a marked increase in energy intake 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 seven men who were resident in, but not confined to, a metabolic suite for 2 wk/diet. This added a component of increased physical activity. The fat, carbohydrate, and protein contents, respectively, of each diet (as a percent of energy) were as follows: low-fat (LF), 20:67:13; medium-fat (MF), 40:47:13; and high-fat (HF), 60:27:13. Energy density increased as the percent of fat in the diet increased. Energy intakes from 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, and 9.78 MJ/d, respectively, in our calorimeter study. This finding suggests that diet composition and energy expenditure combined influence energy balance in humans.
authors.affiliation: MRC Dunn Clinical Nutrition Centre, Cambridge, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Stubbs
authors.forename: P
authors.initials: P
authors.lastname: Ritz
authors.forename: W A
authors.initials: WA
authors.lastname: Coward
authors.forename: A M
authors.initials: AM
authors.lastname: Prentice
mesh_terms: D000328:Adult; D002153:Calorimetry, Indirect; D002245:Carbon Dioxide / Q000378:metabolism; D003903:Deuterium; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D004435:Eating / Q000502:physiology*; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D010103:Oxygen Isotopes; D012527:Satiation / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D010103:Oxygen Isotopes; D002245:Carbon Dioxide; D003903:Deuterium