Assessing the Validity of Body Mass Index Standards in Early Postmenopausal Women
Article first published online: 6 SEP 2012
2002 North American Association for the Study of Obesity (NAASO)
Volume 10, Issue 8, pages 799–808, August 2002
How to Cite
Blew, R. M., Sardinha, L. B., Milliken, L. A., Teixeira, P. J., Going, S. B., Ferreira, D. L., Harris, M. M., Houtkooper, L. B. and Lohman, T. G. (2002), Assessing the Validity of Body Mass Index Standards in Early Postmenopausal Women. Obesity Research, 10: 799–808. doi: 10.1038/oby.2002.108
- Issue published online: 6 SEP 2012
- Article first published online: 6 SEP 2012
- Received for review January 19, 2002. Accepted for publication in final form April 09, 2002
- body mass index;
- percentage of fat;
- postmenopausal women;
- receiver operating characteristic analysis
Objective: To examine the relationship between percentage of total body fat (%Fat) and body mass index (BMI) in early postmenopausal women and to evaluate the validity of the BMI standards for obesity established by the NIH.
Research Methods and Procedures: Three hundred seventeen healthy, sedentary, postmenopausal women (ages, 40 to 66 years; BMI, 18 to 35 kg/m2; 3 to 10 years postmenopausal) participated in the study. Height, weight, BMI, and %Fat, as assessed by DXA, were measured. Receiver operating characteristic analysis was performed to evaluate the ability of BMI to discriminate obesity from non-obesity using 38%Fat as the criterion value.
Results: A moderately high relationship was observed between BMI and %Fat (r = 0.81; y = 1.41x + 2.65) with a SE of estimate of 3.9%. Eighty-one percent of other studies examined fell within 1 SE of estimate as derived from our study. Receiver operating characteristic analysis showed that BMI is a good diagnostic test for obesity. The cutoff for BMI corresponding to the criterion value of 38%Fat that maximized the sum of the sensitivity and specificity was 24.9 kg/m2. The true-positive (sensitivity) and false-positive (1 − specificity) rates were 84.4% and 14.6%, respectively. The area under the curve estimate for BMI was 0.914.
Discussion: There is a strong association between %Fat and BMI in postmenopausal women. Current NIH BMI-based classifications for obesity may be misleading based on currently proposed %Fat standards. BMI >25 kg/m2 rather than BMI >30 kg/m2 may be superior for diagnosing obesity in postmenopausal women.