Arabic version: دراسة تشكك في استخدام مؤشر كتلة الجسم كمقياس وحيد لكبار السن

According to SBS News, new research suggests body mass index (BMI) alone may not fully indicate mortality risk for adults aged 65 and over. The study examined 6,905 people in the United States using 14 years of data from the US National Health and Aging Trends Study, covering 2011 to 2024.

Researchers found that overweight status was associated with a lower mortality hazard than normal BMI, particularly among men. Overweight men had a 46 per cent lower mortality hazard, while men with Class I or II obesity had a 51 per cent lower hazard than men in the normal BMI range. Among women, overweight status was associated with a 27 per cent lower mortality hazard; the result for women with Class I or II obesity was not statistically significant.

Waist circumference showed a more consistent association with risk in both sexes. A measurement above 40 inches, or 102 centimetres, for men and above 35 inches, or 89 centimetres, for women was linked to a 24 per cent higher mortality hazard independently of BMI. Men with normal BMI and a high waist circumference had a 33 per cent higher mortality hazard, while women in that group had a 23 per cent higher hazard.

Co-author Dr Bryan Blissmer of the University of Rhode Island said BMI and waist circumference provide complementary information. The researchers said the findings do not mean obesity is protective, but instead illustrate limits of BMI, which is calculated from height and weight and does not distinguish muscle from fat. They recommend considering waist circumference, muscle mass, body composition and overall health when assessing older adults.