If we limit our food purchases to things that we recognize as coming from a farm, foods that are fairly produced and are as local as possible, we will help nudge the system in the right direction, AND it might just be the weight-loss "diet" we've been looking for.
People in rich countries over-consume while people in poor nations starve, and a hefty percentage of the world's grain crops end up as ethanol or animal feed. And one-third of all the food produced for human consumption every year is lost or wasted.
What is profitable is not necessarily edible; food doesn't get along well with assembly lines, farm-chemical runoff and antibiotics. Its quality deteriorates, as do the soils from which it springs and the health of those to whom it is dished out.