Frailty and nutrition: From epidemiological and clinical evidence to potential mechanisms.

Frailty is a geriatric condition characterized by unintentional weight loss, low muscle strength, feeling of exhaustion, reduced physical activity capacity and slow walking speed. Theoretically, nutrition is a factor closely related to the frailty syndrome: all frailty criteria are more or less affected by poor eating habits, whereas frailty itself may have a negative effect on eating and, thus, on the nutritional status. Indeed, research data suggest an association between frailty and specific constituents of diet, namely protein and energy intake, as well as intakes of specific micronutrients. Furthermore, healthy dietary patterns, such as the Mediterranean diet, have been linked to the frailty prevention. In the present narrative review, we critically evaluate cross-sectional, prospective and intervention studies examining the relationship between diet and frailty development and prevention. Potential mechanisms linking nutrition and frailty as well as directions for future research are discussed.