Protein requirement assessment of elderly men on a rice and beans diet

Abstract

This study evaluated the protein requirement of elderly subjects on a rice and beans diet. Eight men, ages 60 to 81 years, participated in studies to determine nitrogen balance response to graded intakes of rice and beans protein within the sub-maintenance to near-maintenance range of nitrogen intake. All subjects were involved in three eight-day study periods, each consisting of one day on a “protein-free” diet and seven days on a test diet. The test diets were assigned in random order, and included 0.25±0.08, 0.46±0.90, and 0.63±0.13 g protein per kilogram of body weight per day, respectively. Only two subjects achieved positive nitrogen balance, both at the highest protein intake. The calculated protein allowance at α=97.5% for this population on a typical Brazilian rice/beans diet was 1.44 g/(kg.d). This amount is approximately twice the recommended allowance for elderly subjects.