Grant: Canada Postdoctoral Research Award (CPRA) program

As we age, many people lose muscle mass and strength, a condition called sarcopenia, which affects about 1 in 7 adults over 65. Sarcopenia increases the risk of falls, hospitalizations, and even death. Eating enough protein is important to help maintain muscle health, but the type of protein may also matter. Animal proteins (like meat, dairy, and eggs) are powerful for stimulating muscle growth, but high intake can increase the risk of heart disease and other chronic illnesses. Plant proteins (such as beans, lentils, and soy) are linked to better heart and metabolic health, but we don't yet know if they are as effective in preserving muscle in older adults. This gap makes it difficult to develop clear dietary recommendations for aging Canadians. This project will combine advanced population-based and clinical research to answer this question. In the first phase, I will study data from the Canadian Longitudinal Study on Aging on 30,000 older adults over six years. I will examine how eating different amounts of animal and plant proteins relates to changes in strength and physical function. I will also use metabolomics, a cutting-edge approach to measure small circulating molecules in the blood, to identify potential "biomarker fingerprints" of plant and animal protein intake. In the second phase, I will run a clinical trial where 300 older adults will follow either a mostly plant-protein diet or a mostly animal-protein diet for 16 weeks, both with high protein intake overall. I will measure their muscle strength, physical function, body composition to determine which diet works best. I will also measure metabolomics to validate biomarkers identified in the first phase. These biomarkers will help us move beyond traditional food questionnaires to assess intake, which often misses details. The results will provide urgently needed evidence to guide dietary guidelines and help older adults stay strong, independent, and healthy for longer.