Prevalence trends in obesity defined by the Relative Fat Mass (RFM) index among adults in the United States: 1999−2018: Abstracts from the 19h Annual World Congress on Insulin Resistance Diabetes & Cardiovascular Disease

Background: The Relative Fat Mass (RFM) is a simple anthropometric
index based on the ratio of height to waist circumference developed
to estimate whole-body adiposity. Among women and men, RFM has
a very high accuracy (N90%) to diagnose fat-defined obesity using
dual energy X-ray absorptiometry. This study estimated the ageadjusted
national prevalence trends of RFM-defined obesity for women
andmen 20-74 years of age in the United States between 1999 and 2018.
Methods: Data were obtained from the National Health and Nutrition
Examination Surveys (NHANES). Obesity was defined as an RFM ≥40%
(body fat %) forwomen and ≥30% for men. These validated RFM cutoffs are
based on their association with increased risk of mortality.
Results: Final dataset for analysis included 42,651 adults. Among women,
the obesity prevalence increased from 50.1% (95% confidence interval,
45.6% to 54.7%) in 1999-2000 to 63.5% (58.9% to 68.0%) in 2017-2018
(linear trend Pb0.001). Among men, the obesity prevalence increased
from 33.0% (29.1% to 37.0%) in 1999-2000 to 46.5% (41.3% to 51.7%) in
2017-2018 (linear trend Pb0.001). Overall, RFM-defined obesity
prevalence increased by 13.6 percentage points from 1999 to 2018 (linear
trend Pb0.001). During the same period, obesity prevalence estimated
using the body mass index increased by 12.3 percentage points (linear
trend Pb0.001).
Conclusion: Among US adults 20-74 years of age, during the period
between 1999 and 2018, the prevalence of obesity, as defined by the RFM,
continued to increase linearly both in women and men. RFM-defined
obesity prevalence was considerably higher among women.