The removal of government intervention would go a long way. We currently subsidize the production of corn so that the cost of buying it is cheaper than the cost of actually producing it. This makes feeding cows, pigs, and chicken (which end up becoming fast and unhealthy food) inexpensive. As a result, fast food appears to be a lot cheaper than healthy food. It's no coincidence that obesity is a larger problem for the poor than those well-off, mainly because the indigent think they can't afford to buy healthy food, and instead turn to fattening, government-subsidized fast foods. Remove the subsidies and you remove the incentive to purchase this unhealthy fast-food. In schools, governments should be focusing on physical education programs that target obesity and also promoting healthier foods in the cafeteria.