Dietary protein intake and body composition, sarcopenia and sarcopenic obesity: A prospective population-based study

Abstract

Background&aims: Obesity and sarcopenia are major health concerns, particularly among older populations. Dietary protein may help preserve muscle mass and function, but high-protein diets, especially from animal sources, may also increase adipose mass. We investigated associations of total, animal, and plant protein intake with body composition trajectories, sarcopenia, and sarcopenic obesity.

Methods: We included 4576 participants (mean age 65.1 years, 56 % women) from the population-based Rotterdam Study. Dietary protein was measured using food-frequency questionnaires at baseline (2004-2009). Body composition was measured every 4-5 years using dual X-ray-absorptiometry. Handgrip strength (HGS) was assessed starting 2006 using a hydraulic dynamometer. Sarcopenia was determined based on low appendicular skeletal muscle and HGS; and sarcopenic obesity risk based on measures of lean mass, HGS and body fat. Analyses used linear mixed models and generalized estimate equation models.

Results: Higher total protein intake was associated with increased BMI over time (mean difference [95 %-confidence interval (CI)]: 0.86 kg/m² [0.01,1.71] per 5E% increase), and increased fat-mass index (1.33 [0.67,1.99]), body-fat-percentage (4.54[2.76,6.31]), and both gynoid and android fat percentage. Higher protein intake was also associated with a higher sarcopenic obesity risk (-0.85[-1.5,-0.2]), but with a lower sarcopenia risk (odds ratio: 0.62 [0.43,0.90]). These associations were mainly driven by animal protein.

Conclusion: Higher protein intake, particularly from animal food sources, is protective against sarcopenia but also linked to a higher obesity risk. A balanced protein intake advice for older persons should be formulated based on individual needs and health status to prevent sarcopenia, obesity, and sarcopenic obesity.

Keywords: Body compositions; Dietary protein intake; Longitudinal cohort study; Sarcopenia; Sarcopenic obesity.