American Journal of Clinical Nutrition, Vol 34, 2078-2087, Copyright © 1981 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Fecal bulk, energy intake, and serum cholesterol: regression response of serum cholesterol to apparent digestibility of dry matter and suboptimal energy intake in rats on fiber-fat diet

MZ Normani, SS Hussain, JK Lim, MJ Albrink, CK Gunnells and GK Davis

Two experiments were conducted in the rat to determine the relationships of serum cholesterol (SC, mg/dl), apparent digestibility of dry matter (DDM, %), and digested energy intake (DE, kcal/day) at suboptimal level of energy. The energies in diet and feces were determined by calorimetry. DE as percentage of the National Research Council requirement (DE%) was suboptimal (70 to 85%). The experiments had four to five isofibrous diets, and no fiber diets, supplemented with 0.2% crystalline cholesterol (CChol). Animals in experiment 1 were fed varying amounts of feed with 18% coconut oil in the diets where as these in experiment 2 were given fixed amounts of feed with either 6 or 18% oil. The following regressions (p less than 0.001) for SC were found: experiment 1: -1157.7 -5.97 DDM +105.5 CCI -1.48 CCI2 (r2 0.35), where CCI = CChol, mg/day; -1888.4 -2.66 DE +120.97 CCI -1.62 CCI2 (r2 0.37). Experiment 2: 762.99 -6.15 DDM -0.8 fat cal % -0.87DE% (r2 0.31), where fat cal % = fat calories % of DE. Data indicate that at suboptimal energy intake, SC was inversely related to (1) DDM, (2) fat cal, and (3) total energy intake. Liver cholesterol lowering effect of the dietary fiber was also observed. The above findings help to elucidate various conflicting reports related to diet and blood cholesterol.