Introduction

Estimates of obesity prevalence based on current BMI are an important but incomplete indicator of the total effects of obesity on a population.

Methods

In this study, data on current BMI and maximum BMI were used to estimate prevalence and trends in lifetime obesity status, defined using the categories never (maximum BMI ≤30 kg/m2), former (maximum BMI ≥30 kg/m2 and current BMI ≤30 kg/m2), and current obesity (current BMI ≥30 kg/m2). Prevalence was estimated for the period 2013–2014 and trends for the period 1988–2014 using data from the National Health and Nutrition Examination Survey. Predictors of lifetime weight status and the association between lifetime weight categories and prevalent disease status were also investigated using multivariable regression.

Results

A total of 50.8% of American males and 51.6% of American females were ever obese in 2013–2014. The prevalence of lifetime obesity exceeded the prevalence of current obesity by amounts that were greater for males and for older persons. The gap between the two prevalence values has risen over time. By 2013–2014, a total of 22.0% of individuals who were not currently obese had formerly been obese. For each of eight diseases considered, prevalence was higher among the formerly obese than among the never obese.

Conclusions

A larger fraction of the population is affected by obesity and its health consequences than is suggested in prior studies based on current BMI alone. Weight history should be incorporated into routine health surveillance of the obesity epidemic for a full accounting of the effects of obesity on the U.S. population.