Talk to them about the foods you select, what nutritional groups they belong to and how such food helps people stay healthy. Have older children plant a garden. They can watch the food grow, and they should be able to taste a big difference between fresh foods and store-bought foods. Involve children in cooking. Older children can prepare whole meals.
Younger ones can add vegetables to the soups or salads.
Have them do this with the nutritious items you have selected as opposed to having them help you bake a cake. Have children chart their food habits. Tell them to keep a record of everything they eat and drink for several weeks and then analyze both the strong and the weak points of their diet. Then encourage them to gradually improve their selections of foods. Be a good role model.