As a result of the rapid shift in dietary and activity patterns, the world is facing a pandemic of obesity. This new global pandemic is rapidly becoming a problem of the poor. Extensive work has been undertaken to document the changes in weight and, to a much lesser extent, in diet, energy expenditures, and activity patterns. Broad-based creative public health actions are needed to offset these larger forces that promote energy imbalance, poor diets, and reduced physical activity. Inaction will result in an acceleration of morbidity, disability, and deaths from major nutrition-related noncommunicable diseases – primarily in developing countries.