(America’s) Farm policies have made low-nutritional commodities exceptionally cheap, providing the food industry with enormous incentive to market processed foods comprised mainly of refined grains and added sugars. In contrast, vegetables, whole fruits, legumes, nuts and high-quality proteins are much more expensive and, in “food deserts,” often unavailable.
—NYT: ‘Opinion | America’s Obesity Budget‘
… as cheap calories have flooded the environment, opportunities to burn off those calories at school, in recreation and through physically active modes of transportation have declined.