The first principle of a healthy diet is simply to eat a wide variety of foods. This is important because different foods make different nutritional contributions.
The second principle is that fruits, vegetables, grains, and legumes, foods high in complex carbohydrates, fiber, vitamins, and minerals, low in fat, and free of cholesterol, should make up the bulk of the calories you consume. The rest should come from low-fat dairy products, lean meat and poultry, and fish.
The third principle is that one should also try to maintain a balance between calorie intake and calorie expenditure, that means never eat more food than the body can utilize. Otherwise, one will gain weight. The more active you are, therefore, the more you can eat and still maintain this balance.
One can also view healthy eating as an opportunity to expand one’s range of choices by trying foods, especially vegetables, whole grains, or fruits, that one doesn’t normally eat. A healthy diet doesn’t have to mean eating foods that are bland or unappealing