On April 18, 2026, nutritionist Guo Jia-ling from Kuo General Hospital warned that adults over 60 who lose weight face nearly double the death risk if their BMI falls below 21.
Guo explained that weight loss in older adults often reduces both fat and muscle, weakening mobility, metabolism, and immunity, while increasing fall risks and prolonging recovery from illness.
She noted that body fat correlates strongly with bone density, especially in women, as fat may stimulate hormone production that supports bone growth and slows bone loss.
According to the U.S. National Health and Nutrition Examination Survey, adults over 70 with a BMI between 25 and 29.9 had a 13% lower death risk compared to those in lower ranges.
A separate study of Chinese adults aged 65 and older found the lowest mortality occurred at a BMI of 24.16 to 25.91, while those below BMI 21 faced close to double the death risk.
For someone 165 cm tall, maintaining 50 to 65 kg was ideal in youth, but after age 70, a weight of 57 to 65 kg was linked to better longevity.
Guo emphasized that muscle loss and malnutrition pose greater threats to older adults than mild overweight, echoing the medical concept of the “obesity paradox.”
Fu Yu-hsiang, director of Xiangzhen Clinic, said he worries more about unexplained weight loss in seniors than slight gains, comparing the aging body to a pre-typhoon disaster warehouse that needs reserves to withstand shocks.
Huang Guo-jin, deputy director of National Taiwan University Hospital, added that Taiwan’s population shows lowest mortality at a BMI of 24 to 26, with natural energy storage increasing with age to cope with disease and stress.
He clarified that while mild overweight may be beneficial, a BMI over 30 still raises risks of physical frailty and dysfunction.
What BMI range is linked to the lowest death risk in adults over 65?
According to research cited in the report, adults aged 65 and older in China had the lowest mortality when their BMI was between 24.16 and 25.91.
Why might slight weight gain be beneficial for older adults?
Body fat may stimulate hormone production that supports bone growth and slows bone loss, particularly in women, helping to reduce fracture risks from falls.