DrFuhrman's Prescription for Improving and Maintaining Great Health: Nutritional Excellence The quality of a diet can be based on three simple criteria: 1.  Levels of micronutrients (vitamins, minerals, phytochemicals) per calorie. 2.  Amounts of macronutrients (fat, carbohydrate, protein) to meet individual needs, without excessive calories that may lead to weight gain or health compromise. 3. Avoidance of potentially toxic ...