Samenvatting

Background: Aging is accompanied by a progressive loss of muscle mass and muscle strength, also called sarcopenia. Adequate protein intake and distribution influences myofibrillar protein synthesis (MPS) and might therefore be important in the prevention of sarcopenia. Whether the daily amount and distribution of dietary protein is associated with muscle mass and muscle strength in older adults remains to be explored. Objective: The aim of this study was to determine whether the amount of dietary protein and distribution of protein throughout the day is associated with muscle mass and muscle strength in older adults aged 55 years and older. Method: This cross-sectional study included 66 men and 154 women (aged 55 to 91) from the VITAMINE study with available data including; body-composition (dual energy X-ray absorptiometry), dietary protein intake (3-day food diary) and muscle strength (handgrip strength). The coefficient of variation (CV) of protein intake at breakfast, lunch and dinner was used to calculate protein distribution across the main meals. Multivariate linear regression analysis was used to examine the associations of dietary protein intake and protein distribution with muscle mass and muscle strength. Results: Mean age was 72.1 ± 6.5 years, mean absolute protein intake was 77.1 ± 20.8 grams and relative intake was 1.7 ± 0.3 (g/kg BW). Distribution of protein was skewed across the day with most protein at the dinner. In this group of community dwelling older adults aged 55 and older, associations of dietary protein intake (g/kg BW) and protein distribution with skeletal muscle mass index and handgrip strength were found but these associations were not significant. Appendicular lean mass (ALM), Body Mass Index (BMI), age and gender were important confounders that influenced these associations. Conclusion: The results of this study suggests that more research is needed to make any recommendations about protein intake and protein distribution in the prevention of sarcopenia. Studies should be carried out to clarify the effect of protein intake and distribution on muscle mass and muscle strength. The dietician can be of worth in the prevention of sarcopenia by implementing the recommendation of 0.4 g/ kg BW per meal and collecting this data when treating community dwelling older adults.