March 13, 2025
3 min read
Key takeaways:
- Women with intentional weight loss were less likely to die of any cause compared with women who maintained stable weight.
- Mortality risk rose for women with unintentional weight loss or weight gain.
Intentional weight loss of 5% or more, coupled with reduced waist circumference was associated with lower risk for death from cancer, CVD or any cause among postmenopausal women followed for more than 18 years, data show.
In a prospective analysis of more than 58,000 women, researchers also found that intentional weight loss without a reduction in waist circumference was associated only with a reduction in cardiovascular (CV) risk, whereas unintentional weight loss or weight gain were each associated with increased mortality risk.
“Older women who have overweight or obesity should be encouraged to lose weight if they wish to do so,” Michael Hendryx, PhD, professor emeritus Indiana at University Bloomington School of Public Health, told Healio. “The emphasis in weight reduction efforts should be on waist circumference rather than BMI or weight. Women who lose waist circumference intentionally have lower mortality risk over years of follow-up.”
Researchers analyzed data from 58,961 participants aged 50 to 79 years without cancer at baseline from the prospective Women’s Health Initiative Observational Study, who were followed from 1993 through 2023 (mean age, 63 years; mean follow-up, 18.6 years). Researchers assessed measured weight loss and waist circumference reduction between baseline and year 3; women reported whether any weight loss was intentional or not via questionnaire. Researchers categorized participants’ body weight as stable (change of less than 5% from baseline); weight loss (decrease of 5% or more since baseline); and weight gain (increase of 5% or more since baseline).
The primary outcomes included all-cause mortality, cancer mortality, CV mortality and other mortality through follow-up.
The findings were published in JAMA Network Open.
At baseline, mean BMI was 27 kg/m2; mean waist circumference was 84.1 cm. As of February 2023, 49.5% of women had died from all causes, including 15.5% from CV causes, 10.1% from cancer-related causes and 24% from other causes.
Compared with all other women, those with intentional weight loss of 5% or more had lower risk for all-cause mortality (HR = 0.88; 95% CI, 0.86-0.9), cancer mortality (HR = 0.87; 95% CI, 0.82-0.92), CV mortality (HR = 0.87; 95% CI, 0.83-0.91), and other mortality (HR = 0.87; 95% CI, 0.86-0.92). For those who reported intentional weight loss, methods including diet alone, exercise alone and diet plus exercise were all associated with lower morality risk; however, researchers found the associations between mortality risk and intentional weight loss were strongest when women combined methods of diet and exercise.
Intentional weight loss without a reduction in waist circumference was associated only with lower risk for CV death (HR = 0.9; 95% CI, 0.81-0.99) and was also associated with higher risk for other cause of death outcomes (HR = 1.16; 95% CI, 1.08-1.25).
Women who reported unintentional weight loss were more likely to die from any cause (HR = 1.27; 95% CI, 1.24-1.31) and also had higher risk for cancer mortality (HR = 1.25; 95% CI, 1.18-1.32) CV mortality (HR = 1.25; 95% CI, 1.18-1.32) and other mortality (HR = 1.25; 95% CI, 1.19-1.31).
Reductions in waist circumference for women reporting intentional weight loss were associated with reduced all-cause mortality, cancer mortality and CV mortality, whereas an increase in waist circumference or an unintentional decrease in waist circumference was associated with greater mortality risk. All results were unchanged in analyses that excluded women with baseline CVD or diabetes.
“Reasons for divergent findings between weight and waist circumference changes are not entirely clear,” the researchers wrote. “Perhaps older women who attempt to lose weight because they are concerned about adverse health indicators and successful weight loss efforts of 5% or more are not sufficient to offset those conditions. Mortality weight reduction efforts among older women may have other benefits, such as improved functional ability, reductions in cancer incidence, or improved cardiovascular
morbidities.”
Hendryx said more research is needed on the best dietary and exercise practices to help older women lose central adiposity without losing muscle mass.
“Our findings suggest that combining diet and exercise yields the strongest mortality reduction, although we did not assess specific diets or exercise regimens,” the researchers wrote.
For more information:
Michael Hendryx, PhD, can be reached at hendryx@iu.edu.