Food exchange diets take away monotony while keeping to the permissible calorific intake
More than half a century ago, the food exchange lists were created in the USA jointly by the American Dietetic Association, American Diabetes Association and the US Public Health Services. They evolved mainly to help the diabetic patients.
The food exchange system categorises foods similar to the food guide pyramid, namely, starch, meat (protein), vegetables, fruits, milk, fats. In each group the quantities of varied foods that are interchangeable for a constant macronutrient value are compiled.
This system can be compared to the barter because you exchange one food for another that is similar in value. Or sometimes you trade two items for one. This way there is freedom to consume a larger variety of foods instead of following a cumbersome monotonous diet plan.
Where there is no monotony, there is better compliance to diets.
The food exchanges are beneficial especially to the juvenile diabetics and obese children trying to eat within caloric limit and enjoy various foods simultaneously. Following the food exchange lists provides flexibility to the diet plan. A good diet plan is not a single sheet of paper the diabetic takes home and follows for the rest of his life. A satisfying diet plan is one that teaches flexibility, by allowing the diabetic to choose to his liking, a variety of foods from the food exchange lists, as he/she prefers.
Also most often one does not know how to substitute a given food for a favourite alternative and ends up overeating. The food exchange lists teach us, portion control.
A study done on obese premenopausal women by L.Benezro, D. Neiman, C.Neiman, C. Melbey et al demonstrates improved macronutrient quality of diets during “long term moderate energy restriction when the diet is based on food exchange system.”
Each item on the starch list is 80 kcal and 15gm carbohydrate and you could chose between one slice of bread, One-third cup cooked rice, Three-fourth cup dry cereal, half cup cooked oats, one medium chapatti (6” diameter), one idli , half cup cooked dal, half cup potatoes, etc.
Potatoes, sweet potatoes and tapioca too belong in the starch group.
From the vegetable group half cup of cooked vegetable or one cup raw greens equal in their 25 kcal and 5 gm carbs.
Fruit exchange list has portioned fruits to give 60 kcal and 15 gm carbs. Thus these fruits equal in their sugar content – one apple, an orange, 10-15 grapes, 2 dates, three-fourth cup papaya or pineapple, 12 cherries, half banana or mango, one small chikku, or half cup juice, half cup canned fruits etc.
Calorie content of milk varies according to skimmed, low fat or full fat. For the same fat content a cup of curds equal a cup of milk or buttermilk in calories and nutrients.
The meat list is further divided into very lean, lean, medium fat and high fat. Calories differ according to fat content but protein remains the same.
Thus an egg equals its 75 calories to one ounce of medium fat meat/fish or poultry or one ounce of medium fat cheese (ricotto, mozzarella) or half cup legumes cooked.
Fats/oils give 45 kcal per portion and equals in quantity of one tsp oil/ ghee/ mayonnaise/ butter, one tbsp seeds, 6 cashewnuts, 2 walnuts, 2 tbsp shredded coconut, olives 8 large, etc.
Legumes belong to both the meat and starch group and therefore have combined energy and nutritive value.