Medical nutrition therapy (MNT) is the development and provision of a nutritional treatment or therapy based on a detailed assessment of a person's medical history, psychosocial history, physical examination, and dietary history. It is used to treat an illness or condition, or as a means to prevent or delay disease or complications from diseases such as diabetes. The purpose of the assessment is to:
- Determine the persons' need for therapy
- Set parameters to plan a therapy
- Develop a therapy plan
- Determine the best method to initiate the therapy
- Evaluate the effectiveness of the therapy
A medical history includes the assessment of acute or chronic diseases or conditions, as well as any surgeries a person may have had. Medication and drug or alcohol use should also be determined. The evaluation of interactions between food and medications is included because medications may interfere with nutrient absorption or increase the excretion of nutrients. Vitamin, mineral, and herbal supplementation can affect nutritional balance, and interactions with medications are also possible. Knowing the types and amounts of any supplements being taken is important both to determine if the supplementation is needed and to determine if too much of a particular nutrient is being used, which might result in an overdose.
A physical examination includes an assessment of sex, age, and anthropometric data (measurement of height, weight, body mass index, and arm or wrist circumference). The physical appearance of the hair, skin, and nails can assist in identifying nutritional deficiencies. For example, spoon-shaped, pale, and brittle fingernails may indicate an iron deficiency. Paralysis or amputation can affect a persons' ability to eat and increase their risk of certain complications, such as bed sores, which require good nutrition to heal. A person's weight history, such as recent weight changes or rapid weight loss, can be an indicator of a nutritional problem. Knowing if any weight changes were voluntary can affect the direction of a medical nutrition therapy plan.
A psychosocial assessment includes reviewing a person's economic status, ethnic and cultural background, living situation, education level, occupation, mental status, and access to adequate food sources to maintain good health. Each of these components plays a role in determining a person's ability to follow through on specific therapy plans. Handicaps such as mental retardation or blindness may affect a person's ability to prepare meals. The number of people in a household may limit food access or selection if they are on a limited income. In some situations, a recommendation for a change in the person's living situation may be made in order to improve their nutritional health. For example, an elderly person living alone may only eat one meal a day due to limited mobility and low income. Such a person would be a candidate for an assisted-living facility, where meals would be provided.
A diet history includes an assessment of a person's usual dietary intake. This can be done by using any of the following methods: (1) a food frequency questionnaire, (2) a twenty-four-hour recall of food eaten, or (3) a three- to five-day food diary. Reviewing food preparation methods is helpful in determining the amount of sodium and fat in the diet. The frequency of meals eaten out is an important indicator of whether a person enjoys cooking, has access to cooking, or just prefers to eat out instead of cooking. These factors play a role in determining the details of a therapy plan. Other information that is obtained in a diet history includes:
- Is the appetite level good or poor, and has it changed recently?
- Have there been any taste alterations? If so, why?
- Are there any chewing or swallowing difficulties?
- What are the person's bowel habits and have they changed recently?
- Are there any religious restrictions on the diet?
- Are there any food allergies or intolerances?
Medical nutrition therapy is provided by registered dietitians (RDs), who are the only health care professionals with nutrition-specific training. Education includes a bachelor's, master's, or doctoral degree from an accredited university. Required course work is approved by the Commission on Accreditation for Dietetics Education of the American Dietetic Association. After obtaining a degree focused on nutrition and dietetics and completion of a dietetic internship, a national credentialing exam is required. The Commission on Dietetic Registration administers the national examination. Registered dietitians must complete continuing education requirements to maintain their registration status. Advanced certifications can also be obtained through additional training and/or experience. The American Dietetic Association, the American Association of Diabetes Educators, and other nutrition-related organizations recognized within the dietetics profession award these certifications. Dietitians are also commonly referred to as nutritionists. Qualified nutritionists should also have the registered dietitian credentials, and many states require registered dietitians and nutritionist to be licensed.
Registered dietitians are employed in many settings, including: hospitals, health clinics, extended-care facilities, physician offices, home-care companies, private practice, community and public health programs, colleges and universities, school food service, state and federal health and nutrition programs, research organizations, and food or pharmaceutical organizations.
Insurance coverage for the cost of MNT is inconsistent across the United States. Some private insurance companies have policies that pay the cost for a person to receive medical nutrition therapy based on protocols developed by the American Dietetic Association. Other companies leave the coverage to the discretion of a case manager or physician, while some refuse to provide reimbursement for any nutrition therapy.
Some U.S. states have laws that mandate that insurance companies provide coverage for MNT. Some of these states limit coverage to diabetes, while others include a wider range of diseases. In January 2002, the Medicare program began providing MNT coverage for persons with diabetes and prerenal disease. (Medicare is a federal health insurance program for those over the age of sixty-five, those under sixty-five with certain disabilities, and for people with permanent kidney failure.) Congress is considering inclusion of other diagnoses, such as cardiovascular disease. This would expand the provision of MNT to those persons with coronary artery disease, congestive heart failure, and hypertension. Diabetes self-management training is a Medicare-covered benefit that includes MNT and education on issues such as blood glucose monitoring, disease complications, and prevention. Internationally, the cost of nutrition therapy is sometimes covered by a national health care system, or by a private system similar to that in the United States.
Medical Nutrition Therapy is physician directed. This means a person's primary care physician makes a referral to a registered dietitian for therapy. Many insurance carriers and state licensure laws require this referral to document the medical necessity of the therapy.
The expansion of insurance coverage for MNT by Medicare and private providers is vital to improving access to this type of care. Rising health care costs and limited incomes often force choices between food and health care. Medical nutrition therapy has been shown to reduce health care cost for individuals, employers, hospitals, and insurance carriers.
American Dietetic Association (2000). Manual of Clinical Dietetics, 6th ed. Chicago, IL: Author.
Florida Dietetic Association (2002). The Florida Dietetic Association Handbook of Medical Nutrition Therapy: The Florida Diet Manual. Tallahassee, FL: Author.
American Dietetic Association. "Medicare MNT Benefit Provider Information." Available from <http://www.eatright.org>