Association between dairy protein and body composition in middle-aged and older women: A community-based, 12-year, prospective cohort study

Background & aims: Changes in body composition during aging include decreased muscle mass and increased fat mass. Women with low muscle mass with abdominal obesity (LMAO), in particular, could be at higher risk of morbidities and mortality than those with either sarcopenia or obesity alone. Dairy products, which contain whey protein and all essential amino acids, could have a beneficial role in preserving muscle mass and reducing obesity. We aimed to analyze the association between dairy protein and the development of LMAO in women using a large-scale, community-based prospective cohort. Methods: Our analysis included 4251 women from the Korean Genome and Epidemiology Study. Participants were categorized into three groups by the tertile of dairy protein intake, which was assessed using a semi-quantitative 103-food item food frequency questionnaire. Appendicular skeletal muscle mass was estimated using the anthropometric equation. Low muscle mass (LM) was defined as a muscle mass of less than 15 kg in women. Abdominal obesity (AO) was defined as a weight to height ratio of 0.58 or greater. LMAO was defined as LM in combination with AO. Multiple Cox hazard regression analysis was conducted to examine associations between dairy protein intake and incident LMAO. Results: During follow-up (mean, 9.6 years), 280 women newly developed LMAO. According to Cox proportional regression models, the hazard ratios (95% confidence interval) for incident LMAO in the middle and highest tertiles were 0.89 (0.74-1.06) and 0.71 (0.59-0.86), compared with lowest tertile, after adjusting for confounding variables. Conclusions: These findings indicate that high dairy protein intake is inversely related with LMAO development in Korean women. Dairy protein intake could be effective in preventing incident LMAO.restrictio