Background: Weight loss reduces body fat and lean mass, but whether these changes are influenced by macronutrient composition of the diet is unclear. Objective: We determined whether energy-reduced diets that emphasize fat, protein, or carbohydrate differentially reduce total, visceral, or hepatic fat or preserve lean mass. Participants lost 2. Women lost more visceral fat than did men relative to total-body fat loss. Conclusion: Participants lost more fat than lean mass after consumption of all diets, with no differences in changes in body composition, abdominal fat, or hepatic fat between assigned macronutrient amounts. This trial was registered at clinicaltrials. See corresponding editorial on page
Mass mailings were the primary means of recruitment; names were identified with the use of lists of registered voters or drivers. View author publications. However, these associations should be interpreted with caution as the causality cannot be established by observational studies. When the generalized linear model ANOVA identified a between-groups difference, we determined which pairs of groups differed by using the Tukey-Kramer method. Few trials have directly measured changes in visceral or hepatic fat in response to weight-reducing diets 3, 21 — 24, and there remains debate about which, if any, diet or diets are most effective for visceral fat loss, with very sparse data on dietary treatments to reduce hepatic fat accumulation 23 — This finding is consistent with previous studies investigating the long-term effect of low-carbohydrate, high-protein diets on renal markers in individuals with type 2 diabetes without overt kidney disease [ 49, 50 ]. Published : 23 July However, these findings must be interpreted with caution due to their exploratory nature.
The Zone diet, for instance, prescribes 40 percent carbs, preferably complex carbs like veggies and whole grains, 30 percent protein and 30 percent fat. Mean reported intakes at 6 mo and 2 y did not reach target amounts for macronutrients Table 2. Notwithstanding the failure to meet intended targets, each of these trials achieved a large-enough contrast to detect macronutrient effects on body-weight outcomes, although the conditions of these trials were not directly comparable with ours. Magnetic resonance scanning protocol included planning scans, single voxel spectroscopy Point RESolved Spectroscopy [PRESS] for measuring liver fat content and muscle fat content [ 18, 19 ], and chemical shift encoding-based water-fat imaging mDixon for measuring pancreatic fat content, visceral adipose tissue VAT, subcutaneous adipose tissue SAT and waist perimeter. The results for diet effects were similar to those in the primary intention-to-treat analysis except that the loss of subcutaneous abdominal fat was slightly greater in the average-protein than in the high-protein group at 6 mo. The primary outcome was the change in body weight after 2 years in two-by-two factorial comparisons of low fat versus high fat and average protein versus high protein and in the comparison of highest and lowest carbohydrate content. Sports Med ; 24 : 55 — Pratt, Ph. You have free article s left.