The stages of the nutrition transition
Diets move through recognizable stages as societies get richer. First comes scarcity and famine, then a phase of abundant cheap calories heavy in refined grains, sugar, oil and meat, which drives obesity and diet-related disease, and finally, in some places, a hoped-for stage of 'behavior change' where people rebuild healthier patterns. Most of the world is now stuck in the middle stage, where the problem is no longer too little food but too much of the wrong kind.