Appetite loss as a clinical marker of loss of function during aging

Recent literature has shown that appetite loss during aging can lead to negative health outcomes in older adults, particularly malnutrition and mortality. However, its association with functional decline and the mechanisms driving this relationship are not well explored. This review summarizes the current evidence regarding the potential effects of appetite loss on frailty and functional outcomes. Despite the limitations due to heterogeneous methodologies, including study designs, population characteristics, and appetite assessments, most studies indicate that older adults with poor appetite tended to exhibit poor physical performance and increased functional limitations. Furthermore, the simultaneous weight loss in individuals experiencing appetite loss was associated with a higher risk of functional impairments. Finally, emerging evidence connects reduced appetite to biomarkers of aging, including epigenetic alterations, chronic inflammation, and the upregulation of GDF-15. Therefore, loss of appetite is a potential earlier marker of loss of function that deserves further investigation. Adopting a geroscience perspective may enhance our understanding of appetite loss during aging and foster the development of effective interventions.