The Protein Transition in Older Adults

The global population is ageing, accompanied by an increasing prevalence of age-related conditions, including cardiometabolic disease and sarcopenia. Adequate dietary protein intake is essential for healthy ageing, with more than 65% of protein intake in western countries derived from animal-based sources. At the same time, growing concerns regarding environmental sustainability, together with recognised cardiometabolic health benefits of plant-based dietary patterns, are driving a transition towards predominantly plant-based protein diets, referred to as the protein transition. Despite its recognised benefits, the protein transition introduces important scientific and practical challenges. While plant-based dietary patterns may promote cardiometabolic health and environmental sustainability, uncertainty remains regarding their ability to fully support muscle health in older adults. Compared with animal-derived proteins, plant-based proteins may have lower digestibility and less favourable amino acid profiles. However, emerging evidence suggests that combining complementary plant-based protein sources may improve amino acid composition and support both cardiometabolic and muscle health outcomes. The success of the protein transition also depends on feasibility and acceptability in real-world settings. Age-related changes in appetite, sensory perception, and perceived barriers towards plant-based diets may influence adoption among older adults. This review summarises current evidence on protein requirements, protein sources, protein quality, and consumer perspectives relevant to the protein transition and healthy ageing.