Protein and energy utilization in men given a rural Guatemalan diet and egg formulas with and without added oat bran

Healthy men were fed a fiber-free formula diet providing the FAO/WHO Safe Level of egg protein (0.57 g/kg) and a rural Guatemalan diet giving 0.0875 g of protein per kilogram, the recommended dietary allowance for Central America and Panama. For comparison an egg formula diet was fed at the higher protein level, with and without oat bran (0.6 g/kg). All diets maintained nitrogen balance over the 15-day test periods, and balance was distinctly positive at the higher intake of egg protein. Addition of bran doubled the fecal excretion of dry matter and energy; digestibility of energy and protein was reduced 3 to 4%. With the Guatemalan diet, fecal dry matter, nitrogen and energy excretions were nearly four times as high as with egg formula. Relative to egg ( = 100%), protein digestibility of the Guatemalan diet was 78% and total digestible energy was 92%. Present recommended dietary allowances of protein maintain nitrogen equilibrium at an energy intake of 40 kcal/kg in spite of the large fecal losses.