38 CFR § 4.112 - Weight loss and nutrition.
The following terms apply when evaluating conditions in § 4.114:
(a) Weight loss. Substantial weight loss means involuntary loss greater than 20% of an individual's baseline weight sustained for three months with diminished quality of self-care or work tasks. The term minor weight loss means involuntary weight loss between 10% and 20% of an individual's baseline weight sustained for three months with gastrointestinal-related symptoms, involving diminished quality of self-care or work tasks, or decreased food intake. The term inability to gain weight means substantial weight loss with the inability to regain it despite following appropriate therapy.
(b) Baseline weight. Baseline weight means the clinically documented average weight for the two-year period preceding the onset of illness or, if relevant, the weight recorded at the veteran's most recent discharge physical. If neither of these weights is available or currently relevant, then use ideal body weight as determined by either the Hamwi formula or Body Mass Index tables, whichever is most favorable to the veteran.
(c) Undernutrition. Undernutrition means a deficiency resulting from insufficient intake of one or multiple essential nutrients, or the inability of the body to absorb, utilize, or retain such nutrients. Undernutrition is characterized by failure of the body to maintain normal organ functions and healthy tissues. Signs and symptoms may include loss of subcutaneous tissue, edema, peripheral neuropathy, muscle wasting, weakness, abdominal distention, ascites, and Body Mass Index below normal range.
(d) Nutritional support. Paragraphs (d)(1) and (2) of this section describe various nutritional support methods used to treat certain digestive conditions.
(1) Total parenteral nutrition (TPN) or hyperalimentation is a special liquid mixture given into the blood through an intravenous catheter. The mixture contains proteins, carbohydrates (sugars), fats, vitamins, and minerals. TPN bypasses the normal digestion in the stomach and bowel.
(2) Assisted enteral nutrition requires a special liquid mixture (containing proteins, carbohydrates (sugar), fats, vitamins, and minerals) to be delivered into the stomach or bowel through a flexible feeding tube. Percutaneous endoscopic gastrostomy is a type of assisted enteral nutrition in which a flexible feeding tube is inserted through the abdominal wall and into the stomach. Nasogastric or nasoenteral feeding tube is a type of assisted parenteral nutrition in which a flexible feeding tube is inserted through the nose into the stomach or bowel.