The dietary composition of food consumption patterns differs widely across regions. Population level changes, under each dietary group, vary greatly. Dietary patterns within countries also change slowly over time. Dietary Patterns are grouped together in six categories based on similar structures of diets. Each category is named after the food that provides the major part of food energy in the diet. For methodological reasons related to other aspects of the dietary structure, the statistical analysis assigns Japan and Malaysia to the group of countries where maize is the main Calorie provider, even though this is not true of these two countries. See WFS companion paper 4.