In - Your theories on why America is getting fatter. In Your theories on why America is getting fatter. The least helpful contributions are the ones that explain, often in painstaking detail, that obesity is caused by some combination of eating too much and exercising too little.
Some readers speculate that nothing has changed other than the definition of obesity.
Others attribute the obesity explosion to the aging of America. Another nice try, but it doesn't fit the facts. Obesity is growing within every age group. The angriest e-mail comes from readers who believe they've been duped into eating too many carbohydrates and not enough fat. At the same time, the food pyramid discourages you from eating the fats that would assuage your hunger.