Adequate protein intake in older adults in the context of frailty: cross-sectional results of the Nutrition and Health Survey in Taiwan 2014–2017

Background Emerging evidence suggests that a dietary protein intake higher than the current recommended dietary allowance of 0.8 g/kg body weight (BW)/d may be needed to maintain optimal muscle mass, strength, and function in older adults. However, defining optimal protein intake in this age group remains a challenge. Objective In this study we sought to describe the dietary protein intake in frail, prefrail, and robust older Taiwanese adults. Methods Data for 1920 older adults were collected from the Nutrition and Health Survey in Taiwan from 2014 to 2017. Dietary intake was assessed using the 24-h recall method. Frailty was determined using the modified Fried's criteria. Body composition was assessed using DXA. Sex-specific dietary protein intakes, measured as values/kg of BW, fat-free mass (FFM), and lean mass (LM), were estimated for the 3 age groups (65-69, 70-79, and ≥80y) and the 3 frailty levels. Results In both males (P for trend = 0.034) and females (P for trend = 0.015), there were significant downward trends for protein intake/kg of BW with the severity of frailty. The age-adjusted protein intake/kg of BW was still significant in males (P for trend = 0.009), but no longer in females. This phenomenon was also seen for protein intake at lunch and dinner but not at breakfast. Age-adjusted trends for protein intake/kg FFM or LM were not significant in either sex. The median protein intake in robust older males and females was 1.21 and 1.19 g/kg BW/d, respectively, and the mean intakes were even higher. Conclusion Median protein intake in robust Taiwanese older adults was approximately 1.2 g/kg BW/d, with higher mean values. The protein adequate intake in Taiwanese older adults was higher than the current recommended daily allowance (RDA) level but within the RDA range derived from the state-of art indicator amino acid oxidation technique.