Anne N. Hiol

Protein intake, sources and distribution impact on muscle protein synthesis and muscle mass in older adults. However, it is less clear whether dietary protein influences muscle strength. Data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns, cognitive function and metabolic syndrome in older adults aged 65–74 years. Dietary intake was assessed using a 4-d food record and muscle strength using a handgrip strength dynamometer. After adjusting for confounders, in female older adults (n212), total protein intake (β= 0⋅22,P< 0⋅01); protein from dairy and eggs (β= 0⋅21,P= 0⋅03) and plant food sources (β= 0⋅60,P< 0⋅01); and frequently consuming at least 0⋅4 g/kg BW per meal (β= 0⋅08,P< 0⋅01) were associated with higher BMI-adjusted muscle strength. However, protein from meat and fish intake and the coefficient of variance of protein intake were not related to BMI-muscle strength in female older adults. No statistically significant associations were observed in male participants (n= 113). There may be sex differences when investigating associations between protein intake and muscle strength in older adults. Further research is needed to investigate these sex differences.

Background: Animal protein sources are more efficient in increasing muscle protein synthesis and maintaining muscle mass in older adults, but little is known about when they are consumed across the day in New Zealand (NZ) older adults. Objectives: to investigate sources of protein across the day and at each meal in community-dwelling older adults living in NZ. Methods: data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns and associations with cognitive function and metabolic syndrome in adults aged 65 to 74 years. Dietary intake was collected using a 4-day food record. Sources of protein intake were assessed across the day and at breakfast, midday and the evening meal. Results are presented as a percentage of the total protein intake for the day and for each meal. Results: participants (n = 327; 65.4% female) had a median relative protein intake of 1.2 [0.9, 1.4] g/kg in males and 1.1 [0.9, 1.3] g/kg in females. At breakfast, participants primarily consumed protein from milk (28.1%), breakfast cereal (21.6%) and bread (12.2%). Protein intake at the midday meal was derived from bread (17.4%), cheese (9.5%) and milk (9.2%). At the evening meal, 21.2%, 15.2% and 13.6% of total protein was derived from red meat (beef, lamb, pork), poultry and fish, respectively. Conclusion: in this cohort, cereals and dairy products at breakfast and the midday meal, and meat sources at the evening meal contributed the most to daily protein intake.

Background: Aging is associated with decreases in muscle strength and simultaneous changes in body composition, including decreases in muscle mass, muscle quality and increases in adiposity. Methods: Adults (n = 369; 236 females) aged 65–74 years living independently were recruited from the cross-sectional Researching Eating Activity and Cognitive Health (REACH) study. Body fat percentage and appendicular skeletal muscle mass (ASM) (sum of lean mass in the arms and legs) were assessed using Dual-energy X-ray Absorptiometry (Hologic, QDR Discovery A). The ASM index was calculated by ASM (kilograms) divided by height (meters) squared. Isometric grip strength was measured using a hand grip strength dynamometer (JAMAR HAND). Results: Linear regression analyses revealed that muscle strength was positively associated with the ASM index (R² = 0.431, p < 0.001). When exploring associations between muscle strength and muscle mass according to obesity classifications (obesity ≥30% males; ≥40% females), muscle mass was a significant predictor of muscle strength in non-obese participants. However, in participants with obesity, muscle mass was no longer a significant predictor of muscle strength. Conclusions: Body fat percentage should be considered when measuring associations between muscle mass and muscle strength in older adults.

Objectives: To investigate associations between body composition and muscle strength in older