Table 1.

Similarities between characteristics of protein-energy malnutrition (PEM)/undernutrition and frailty in older adults

Characteristic	Protein-energy malnutrition/undernutrition	Physical frailty
Prevalence in community-dwelling older adults	Not well documented but thought to be low for both conditions, may be higher in specific populations
Subacute state exists	✓	✓
Measures available for screening in the community	✓	✓ Yes, but under development
Definition	Primary (modifiable) undernutrition due to inadequate intake of food to meet nutritional requirements	Disuse atrophy and age-related sarcopenia
Recognizable characteristics (phenotypes)	✓ BMI < 20 kg/m2 or 10% weight loss at follow up BMI < 22 in ages 70+ [33]	✓
Diagnosis	✓ Differential diagnosis needed to separate primary PEM/undernutrition from secondary PEM with other causes, and mixed primary and secondary conditions	✓ Differential diagnosis needed to separate primary disuse atrophy-related frailty from secondary causes of frailty and sarcopenia, and mixed primary and secondary conditions
Outcomes	✓	✓
Modifiable determinants	✓ Yes, for primary PEM; varies for secondary PEM due to etiology, and mixed primary and secondary PEM	✓ Yes, for poor nutrition, and disuse atrophy-related frailty; varies for others
Treatments	Helpful to treat both PEM and frailty together since they are strongly related to each other