Impact of Meeting Different Guidelines for Protein Intake on Muscle Mass and Physical Function in Physically Active Older Women

Abstract

The role of dietary protein intake on muscle mass and physical function in older adults is important for the prevention of age-related physical limitations. The aim of the present study was to elucidate links between dietary protein intake and muscle mass and physical function in older women meeting current guidelines of objectively assessed physical activity. In 106 women (65 to 70 years old), protein intake was assessed using a 6-day food record and participants were classified into high and low protein intake groups using two Recommended Dietary Allowance (RDA) thresholds (0.8 g·kg−1 bodyweight (BW) and 1.1 g·kg−1 BW). Body composition, aerobic fitness, and quadriceps strength were determined using standardized procedures, and self-reported physical function was assessed using the SF-12 Health Survey. Physical activity was assessed by accelerometry and self-report. Women below the 0.8 g·kg−1 BW threshold had a lower muscle mass (p < 0.05) with no differences in physical function variables. When based on the higher RDA threshold (1.1 g·kg−1 BW), in addition to significant differences in muscle mass, women below the higher threshold had a significantly (p < 0.05) higher likelihood of having physical limitations. In conclusion, the present study supports the RDA threshold of 0.8 g·kg−1 BW of proteins to prevent the loss of muscle mass and emphasizes the importance of the higher RDA threshold of at least 1.1 g·kg−1 BW to infer additional benefits on constructs of physical function. Our study also supports the role of protein intake for healthy ageing, even in older adults meeting guidelines for physical activity.

Dietary Fibre May Mitigate Sarcopenia Risk: Findings from the NU-AGE Cohort of Older European Adults

“…Altogether, our findings support the promotion of increased FI in older adults for the maintenance of muscle mass. We and others have previously highlighted the beneficial impact of adequate protein intake on muscle mass in older adults [8,43,44]. In this respect, the fact that the impact of protein intake on muscle mass was accounted for in the current study further strengthens the proposed beneficial role of adequate FI in the regulation of muscle mass.…”

“…Healthy dietary habits and engagement in regular physical activity have been advocated by major health organisations in order to mitigate the age-related loss of muscle mass [8,9]. In this respect, adherence to healthy dietary patterns, including the Mediterranean Diet and the Dietary Approach to Stop Hypertension (DASH), has been linked to beneficial health effects in older adults [10,11].…”

“…Importantly, in order to depict the true impact of FI on muscle mass, other features of a healthy diet must be considered. For example, we have previously shown that adherence to recommended intakes of proteins is associated with a higher muscle mass in older women [8]. Moreover, as regular exercise has established effects on the maintenance of muscle mass and function, information on objectively assessed physical activity (PA) levels needs to be considered when exploring the impact of diet.…”

Amount Rather than Animal vs Plant Protein Intake Is Associated with Skeletal Muscle Mass in Community-Dwelling Middle-Aged and Older Chinese Adults: Results from the Guangzhou Nutrition and Health Study

“…10,11 However, previous epidemiological studies have produced conflicting results. Higher protein intake was associated with greater muscle mass and less decline in muscle mass in most observational studies [12][13][14][15][16] but not all. 17 In addition, evidence from randomized clinical trials showed either beneficial or no effect of protein supplementation on preserving muscle mass in older adults.…”

Sarcopenic Characteristics of Active Older Adults: A Cross-sectional Exploration.

“…However, the majority of these studies are conducted in free-living community dwellers, with limited studies in physically active older adults. One of the few studies in active older adults compared protein intakes and physical function in active (150 mins per week of moderate-to-vigorous activity) older (67.5 ± 1.8 years) women and found a signi cant difference in self-reported physical function -as measured using hand grip strength and short physical performance battery (SPPB) -in women with higher protein intakes (>1.1g/kgBM per day) compared to low protein intakes (0.8g/kgBM per day) (56). Additionally, a recent systematic review and meta-analysis of observational studies assessing protein intake with various physical performance outcomes found that reasonably high high (1.0g/kgBM per day) and very high protein intakes (>1.2g/kgBM per day) were associated with more favourable lower-limb physical performance (P<0.05) and lower limb strength (P=0.05) when compared to low protein (<0.8g/kgBM per day) in community dwelling older adults.…”