Dietary modification involves comprehensive changes in eating patterns to achieve pre-determined goals. Examples of such goals include weight loss, reduced fatigue, normalization of blood pressure, improved lipid profile or blood glucose control, or management of irritable bowel syndrome or any other chronic conditions and ailments.
Techniques may include modification of macronutrient content (protein, carbohydrate, fat), micronutrients (vitamin, mineral, and trace elements), or non-nutritive compounds (phytochemicals and fiber). Certain foods may also be eliminated if there is reason to believe that a sensitivity, intolerance, or allergy to these foods exists.
Examples of modified diets to treat specific conditions include the Feingold diet for ADD/ADHD which eliminates food additives; gluten/casein free diets for restrictive airway disease; and the low glycemic index/Syndrome X diet for the treatment of hyperinsulinemia, hyperglycemia, and obesity. The use of functional foods to modify the diet may include the use of teas, juices, broths or edible flowers chosen for their specific nutrient content.
Dietary supplementation may be indicated to replete subclinical or overt deficiencies as determined by a qualified healthcare practitioner. Deficiencies may be related to inadequate intake of nutrients due to poor dietary intake or excessive losses or increased needs due to illness. Dietary supplementation may also be indicated to treat certain chronic or acute conditions. Examples include evening primrose oil and vitamin B6 for premenstrual syndrome; garlic or soy protein isolate to lower cholesterol; ginger to treat postoperative nausea and vomiting or relieve morning sickness; or St. Johns wort and SAM-E to treat mild depression.