Hypotheses abound concerning the origins of the global obesity epidemic. Genetic predisposition, maternal obesity, excessive maternal weight gain, diabetes, tobacco use during pregnancy, and prenatal exposure to obesogens or endocrine disruptors have all been implicated.
An international survey of more than 300 policymakers reported that more than 90% believed personal motivation was a strong or very strong influence on the rise of obesity. We describe how simple descriptive statistics can explain a great deal about what factors may, and may not, have caused the rapid rise in prevalence of obesity in the USA, where this phenomenon was first apparent.
Since 1960, the National Health Examination Study and National Health and Examination Surveys (NHANES) have been done on a regular basis, by the US Centers of Disease Control, among representative samples of the general population (non-institutionalised population).
Height and weight are measured in a standardised fashion, and are used to calculate body mass index. Results are shown for men and women of different ages. Similar patterns to those shown in the were seen when trends were graphed separately for non-Hispanic white, non-Hispanic black, and Mexican American men and women.