In nutrition, the diet is simply the total amount of calories ingested by an organism or person. It can be categorized into several types, each with its own definition. The four types of dietary categories are nutritional classifications; functional classifications; quantitative classifications; combination classifications; and food additive classifications. The classification system of dietary assessment is commonly known as NDL, or Nudworth criterion.
The first classification is nutritional classifications, which include; total nutrition, nutrient class, functional classification, and food additive classifications. This particular diet type focuses on the macro-nutrient content of foods, rather than their nutrient content per se. Common examples of these foods include fruits, vegetables, whole grains, dairy products, meats, and fish. As foods become part of our daily diet, these become important factors in defining our diet.
The second diet type is functional classification. This particular diet type defines appetite. According to this diet type, the desire for food is measured by the metabolic activity of the human body. According to this belief, a diet that is low in calories but high in carbohydrates is effective in reducing appetite, thereby making a diet soft drink a weight loss diet solution. The consumption of carbohydrate-rich diet soft drinks satisfies the energy demands of the body and provides a feeling of fullness, thus tricking the brain into registering that a particular amount of energy has been consumed.
The third diet type is quantitative classifications, which include; diabetic diet, non-diabetic diet, and vegetarian diet. A diabetic diet consists of mainly rice, breads, pasta, cereals, potatoes and legumes. On the other hand, a non-diabetic diet consists of vegetables, fruits, nuts and seeds. A vegetarian diet is inclusive of meat, seafood, and legumes.
The fourth dietary concept is food group classification, which defines four broad categories: nutrient dense food, fruit and vegetable-rich food, grain food and legume food. All these food groups can be classified into nutrient-dense food and fruit and vegetable-rich food. These food groups contain more nutrients than the others and are more easily digested. Also they contain all the essential nutrients required by the body to function properly.
The fifth food group is grain food. This particular food group consists of foods such as whole-grain breads, cereals, pasta and bran cereals. They contain no fat, sugar or salt and are rich in various vitamins, minerals and fiber. They are easily digested and are good for weight control.