Clinical nutrition is nutrition of patients in health care. Clinical in this sense refers to the manage of patients, not only outpatients at clinics, but also, and actually mainly, inpatients in hospitals. It incorporates mainly the scientific fields of nutrition and dietetics. It aims to keep a healthy energy balance in patients, as well as providing sufficient amounts other nutrients such as protein, vitamins, minerals.
Methods of nutrition 
Among the routes of administration, the preferred means of nutrition is, if possible, oral administration. Alternatives include enteral administration (in nasogastric feeding) and intravenous (in parenteral nutrition).
Clinical malnutrition 
In the field of clinical nutrition, malnutrition has distinct causes, epidemiology and management than malnutrition that is mainly associated with poverty.
The main causes of clinical malnutrition are:
- Cachexia caused by diseases, injuries and/or aging
- Difficulties with ingestion, such as stroke, paresis, dementia, depression, dysphagia
There are various definitions of clinical malnutrition. According to one of them, patients are defined as severely undernourished when meeting at least one of the following criteria: BMI < or = 20 kg/m2 and/or > or = 5% unintentional weight loss in the past month and/or > or = 10% unintentional weight loss in the past 6 months. By the same system, the patient is moderately undernourished if they met at least one of the following criteria: BMI 20.1–22 kg/m2 and/or 5-10% unintentional weight loss in the past six months.
See also 
- Kruizenga HM, de Vet HC, Van Marissing CM, et al. (2010). "The SNAQ(RC), an easy traffic light system as a first step in the recognition of undernutrition in residential care". J Nutr Health Aging 14 (2): 83–9. PMID 20126953.
- "Advertising in The American Journal of Clinical Nutrition". Retrieved June 18, 2009.