Stemming the Obesity Epidemic: A Tantalizing Prospect

Abstract

Obesity is a growing problem worldwide, but there are no good methods to assess the future course of the epidemic and the potential influence of interventions. We explore the behavior change needed to stop the obesity epidemic in the U.S. We modeled the population distribution of BMI as a log-normal curve of which the mean shifts upward with time due to a positive population energy balance. Interventions that decrease food intake or increase physical activity result in more favorable trends in BMI. The recently observed trend in average BMI implies that the average U.S. adult over-consumes by approximately 10 kcal/d. If this trend continues unaltered, obesity prevalence will exceed 40% for men and 45% for women in 2015. To stop the epidemic, it suffices to decrease caloric consumption by approximately 10 kcal or walk an extra 2 to 3 minutes per day, on average. This leads to a paradox: little behavior change seems sufficient to halt the epidemic, but in practice this proves hard to achieve. The obesogenic environment is the likely culprit. Individuals trying to maintain a healthy weight need to be supported by environments that stimulate physical activity and do not encourage over-consumption. Research should show what measures are effective.