DIFFERENTIAL METABOLIC EFFECTS OF ENERGY RESTRICTION IN DOGS USING DIETS VARYING IN FAT AND FIBER CONTENT

The role of dietary fat and fiber in energy restriction for the manage ment of obesity was examined, Twelve male castrated dogs were energy r estricted for 7 weeks by feeding 60% of their calculated maintenance e nergy requirements (MER = 1500 kcal/m(2)/d) for ideal body weight, Six dogs were restricted on a high-fat (35.4 kcal% from fat), low-fiber ( 2.9% dry matter basis [DMB]) diet while the other six dogs were restri cted on a low-fat (24.5 +/- kcal% from fat), high-fiber (27% DMB) diet , Compared with the high-fat, low-fiber diet, energy restriction on th e low-fat, high-fiber diet resulted in significantly greater decreases in body fat (1472 +/- 166 vs, 853 +/- 176 g; p < 0.05) and total seru m cholesterol concentrations (108.7 +/- 11.3 vs. 51.5 +/- 13.9 mg/dL; p<0.005), Reductions in body weight (286 +/- 0.3 vs. 2.14 +/- 0.3 kg; p<0.09), and mean arterial blood pressure (17.4 +/- 6.1 vs. 6.7 +/- 2. 9 mmHg; p<0.12) were also greater on the low-fat diet; however, these diet effects did not reach statistical significance, These data sugges t that the fat and fiber content of the diet during energy restriction are important factors in the management of obesity.