Older adults can be categorized into three subgroups to better develop and implement personalized interventions: the “disabled’’ if needing assistance in the accomplishment of basic activities of daily living (ADL), the “frail” if limitations and impairments are present in the absence of disability, and “robust” if there is no frailty or disability present. However despite evidence linking frailty to poor outcomes, frailty is not a criterion for implementation of clinical interventions in most countries.Since many elderly are not identified as frail, they frequently are treated inappropriately in healthcare settings.Assessment of frailty or pre-frailty in older adults is recommended to preventively act before the irreversible cascade of disability commences. Clinical characteristics of frailty (weakness, low energy, slow walking speed, low physical activity and weight loss) underline the links between nutrition and frailty.Physical frailty is also associated with cognitive frailty. At the Gérontopôle Frailty Clinics, France, nearly 40% of patients referred by their primary care physician to evaluate frailty have significant weight loss (more than 4.5 kg in the past 3 months), 83.9% of patients present with slow gait speed, 53.8% were sedentary, and 57.7% had poor muscle strength. Moreover, 43% had a Mini Nutritional Assessment (MNA®) score less than 23.5 and 9% less than 17, reflecting risk for and malnutrition respectively. Of those with physical frailty, more than 60% have some cognitive impairment. In this paper we review clinical evidence on undernutrition and frailty and the potential for current interventions to help prevent frailty and disability with aging.