Protein-Enriched Foods: A Promise Older Adults Will Accept? A systematic review of consumer acceptance in later life

Protein consumption is essential for healthy ageing, yet many older adults fail to meet recommended levels. Protein-enriched foods have been proposed as an intermediate solution between habitual diets and oral supplements; however, their acceptance among older adults remains inconsistent. This systematic review synthesizes factors influencing the acceptance of protein-enriched foods among adults aged 65 years and older. Following PRISMA guidelines, 14 peer-reviewed studies were analyzed using a multilevel framework encompassing product-related, individual, and sociocultural determinants. Influencing factors were classified as barriers, facilitators, neutral, or debated variables and synthesized according to their frequency and explanatory emphasis across analytical levels. Across 43 identified determinants, acceptance was primarily constrained at the microlevel: when taste, texture, or ease of consumption were compromised, protein-enriched foods were generally rejected. On the meso-level, psychological and social factors, including familiarity, perceived health relevance, and professional endorsement helped to foster acceptance, once sensory and physiological requirements were met. Lastly, on the macro-level sociocultural factors shaped legitimacy and trust but exerted limited influence in the absence of satisfactory functional acceptability. Overall, acceptance of protein-enriched foods in later life emerges as a hierarchically structured, multilevel process in which product characteristics and consumer physiology delimit choice, while psychological and sociocultural factors condition openness, relevance, and sustained adoption. Designing protein-enriched foods that feel familiar, enjoyable, and worth eating may therefore be as critical as their nutritional potential for supporting everyday eating in older age.