Medical Nutrition Therapy · What Is It, Uses, Examples, and More

Medical nutrition therapy is usually recommended by a healthcare provider and thoroughly assessed by a registered dietitian-nutritionist (RDN) who works closely with the individual and medical team to establish an individualized nutrition plan. 

The first step of medical nutrition therapy is a nutrition assessment, which collects information about the individual’s nutritional status and related health conditions. A nutrition assessment involves obtaining body measurements that can be used to assess body composition, such as height and weight, body mass index (BMI), skin fold thickness, and arm or leg circumference. Sometimes, blood tests may be conducted to determine the individual’s nutritional status, such as glucose, glycated hemoglobin (HbA1c), cholesterol and triglyceride levels, prealbumin, vitamins, and micronutrients (e.g., sodium, potassium, calcium, phosphate, etc.). Next, a dietary assessment, including an estimation of the total calorie intake and daily dietary intake, can help the dietitian understand the individual’s eating habits, portion sizes, cooking methods, and overall diet quality. Other factors that can influence one’s diet and may be considered include changes in smell or taste; use of dentures; swallowing difficulties; risk of food aspiration; food intolerances; and taste preferences. 

In addition to nutrition assessment, the nutritional professional may consider the underlying disease, choose appropriate nutrition interventions, and subsequently monitor and evaluate the response to treatment over time.

Medical nutrition therapy is used in a wide variety of medical conditions. For example, individuals with diabetes mellitus can benefit from medical nutrition therapy to improve their glucose control and prevent long-term complications. Likewise, medical nutrition therapy can help lose weight and improve nutritional status in individuals with obesity or cardiovascular risk factors, such as high cholesterol or hypertension. It may also be recommended in individuals with gastrointestinal disorders, such as gastroesophageal reflux disease, celiac disease, inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), and short bowel syndrome, as in those with liver or kidney disease. 

In some cases, medical nutrition therapy is used to prevent or treat malnutrition in individuals with chronic illnesses, those hospitalized for an extended period, or have undergone major surgery. It can also be part of treatment in individuals with metabolic disorders or severe food intolerances who require strict diets. 

Examples of medical nutrition therapy include behavioral and lifestyle changes, such as changing one’s eating habits, eating a balanced diet, and maintaining an active lifestyle. In other cases, individuals may benefit from specific diets that restrict certain foods or food groups. Examples include a low carbohydrate diet in individuals with diabetes mellitus, a gluten-free diet in individuals with celiac disease, or a diet low in FODMAPs (i.e., short-chain fermentable carbohydrates) in individuals with irritable bowel syndrome. Some individuals may also require adding vitamins or supplements to prevent or treat nutrient deficiencies and malnutrition. 

When individuals have trouble with oral intake or digestion, it may be necessary to provide artificial nutrition, which uses preparations specifically formulated to provide the appropriate amount of fats, proteins, sugars, and minerals depending on the individual’s energetic requirements. These artificial preparations can be delivered into the stomach or small intestine to be absorbed by the gastrointestinal tract, known as enteral nutrition. Alternatively, artificial nutrition may be delivered directly to the bloodstream through a tube inserted into a vein known as parenteral nutrition. Enteral nutrition is preferred in most situations as it is more physiological and has fewer side effects than parenteral nutrition. However, parenteral nutrition may be necessary when enteral nutrition is contraindicated, not tolerated, or insufficient to meet the individual’s metabolic needs.