Effect of the level of dietary protein intake on fat absorption in children
Related Experiment Videos
Abstract:
The quantity and quality of protein in the diet affect both nitrogen balance and energy utilization in man. One possible mechanism is by a direct effect on the process of fat digestion and absorption. The effect on fat absorption of feeding diets providing 0%, 6.4%, or 12.5% of energy as protein was assessed in nine children. Liquid diets were prepared by high speed blending of calcium caseinate, a soy-cottonsed oil blend (80:20), sucrose, water, vitamins, and a mineral mixture and fed by bottle five times per day. Diets varied in the amount of protein and were fed to maintain constant the intakes of fat and carbohydrate. All children began by consuming the diet providing 6.4% of energy as protein for a period of 6 days: 3 days of adaptation, 3-day dietary periods and metabolic collections followed in one of two sequences: 12.5%, 0%, 6.4% energy as protein in five children; 0%, 12.5%, 6.4% energy as protein in four. Mean fat excretion during the two 6.4% periods did not differ significantly (initial 14.5 +/- 6% of intake; final, 11.7 +/- 5.0% of intake). Fat excretion was significantly greater during the period when no protein was consumed (23.9 +/- 7.7% of intake) than during either the period in which protein provided 6.4% of energy (P less than 0.01) or during that in which protein provided 12.5% of energy (10.0 +/- 2.6% of intake, P less than 0.001). The difference between the 6.4% and 12.5% periods did not attain significance (P = 0.10). Fecal fat expressed as a percentage of fecal dry weight was significantly greater during periods when the diet contained no protein than during periods in which protein provided either 6.4% (P less than 0.05) or 12.5% (P less than 0.01) of energy. Additional studies were carried out in a similar fashion in six children consuming diets in which protein provided 5%, 9.6%, and 15% of energy. All six possible dietary sequences were used. At these intakes fat excretion did not vary significantly with protein intake.