Being unfit is an independent predictor of all-cause mortality, even after adjustment for body fat, according to a new study (JAMA 2007; 298:2507–16).
The study followed 2,603 adults aged 60 or over for a mean of 12 years. Results showed that obese subjects who were fit had a lower risk of dying than normal-weight subjects who were physically inactive. While fitness predicted mortality risk regardless of smoking, baseline health, body mass index, waist circumference or body-fat percentage, waist circumference was not associated with increased mortality after fitness was considered.
“Normal-weight individuals in our study had greater longevity only if they were physically fit; furthermore, obese individuals who were fit did not have increased mortality,” the authors report. “It may be possible to reduce all-cause death rates among older adults, including those who are obese, by promoting regular physical activity, such as brisk walking for 30 minutes or more on most days of the week,” they conclude.