A new study has found that a larger waist circumference may be a stronger warning sign for mortality risk in older adults than body mass index (BMI) alone. Researchers found that older people with a high waist circumference had a 24% higher risk of death, highlighting the importance of abdominal fat when assessing long-term health.
The study, published in the Journal of the American Geriatrics Society, analysed data from 6,905 adults aged 65 and older who were followed between 2011 and 2024. Researchers examined both BMI and waist circumference to determine how different measures of body size were associated with the risk of death from any cause.
The findings revealed an important difference between BMI and waist size. While higher BMI was associated with a lower mortality risk among some older adults, elevated waist circumference remained associated with increased mortality risk, even after taking BMI into account. This suggests that simply looking at body weight may not provide a complete picture of a person’s health risks.
Among men, being overweight was associated with a 46% lower risk of death, while class I and class II obesity were associated with a 51% lower risk compared with men in the normal-weight category. Similar patterns were observed among women, although the relationship between BMI and mortality differed by sex.
However, researchers found that abdominal obesity told a different story. A waist circumference above approximately 40 inches in men and 35 inches in women was associated with a 24% greater mortality risk. The researchers also observed that increasing waist size was linked with progressively greater risk.
Experts explain that waist circumference can provide information about visceral fat, which is stored around internal organs such as the liver, heart, kidneys and digestive organs. This type of fat is considered metabolically active and has been linked to several health problems.
The findings also highlight limitations of BMI, which is calculated using height and weight but does not directly measure where fat is stored or distinguish between muscle and fat. Experts therefore suggest that waist circumference and BMI can provide complementary information when evaluating health risks, particularly among older adults.
Researchers stressed that the results do not mean having a higher body weight is automatically healthier or that people should ignore established obesity-related risks. Instead, the study suggests that healthcare professionals may benefit from considering both overall body size and waist measurements when assessing the health of older patients.
