In these KQED Lowdown infographics, explore how adult obesity rates in the United States, as measured by body mass index (BMI), have dramatically changed in the past half-century. A circular graph and a pictograph depict data by decade, indicating which parts of the population were not overweight, overweight, obese, and extremely obese according to BMI. In the accompanying classroom activity, students develop an understanding of the ratios and proportional relationships by examining numerical data found in the graphs and creating their own bar graphs.