Nutritional status related to poor health outcomes in older people: Which is better, obese or lean?

Good nutritional status is crucial for maintaining growth and health in all stages of life. However, the relationship between nutritional status and health and the effect on various health-related outcomes differ, depending on the life stage. Many adverse outcomes in older adults, directly linked to different nutritional status, are not present in middle-aged adults, and their ideal nutritional status may differ. This article will review the optimal nutritional status, mainly evaluated by anthropometric measurements such as body mass index, for older adults from various perspectives. Overall, in older adults low body mass index is at higher risk of health problems such as mortality and difficulties in physical functioning compared with middle-aged adults, reducing the risk of health problems for overweight and (abdominal) obesity. Overweight may be more beneficial than lower level of normal weight in older-old and vulnerable older people. While, with or without obesity, skeletal muscle loss or weakness as well as unintentional weight loss induces health problems in older adults. The impact of metabolic syndrome on the prognosis of older adults is clearly reduced compared with middle-aged adults, requiring a shift in medical attention in older adults from metabolic syndrome to frailty. There are still many unclear points regarding the optimal nutritional status of older people, and further research is needed to support healthy longevity. Geriatr Gerontol Int 2021; 21: 5-13.