Chronic obstructive pulmonary disease （COPD） is an inflammatory disease of the lungs that is characterized by a progressive airflow limitation. COPD is caused mainly by long-term inhalation exposure to noxious substances such as cigarette smoke. Patients with COPD are at high risk of malnutrition （25-40%）. Malnutrition is a well-known risk factor for poor prognosis in patients with COPD. The main cause of malnutrition are energy imbalance and lung cachexia that results from systemic inflammation. The proinflammatory cytokines, such as tumor necrosis factor-alpha （TNF-α）, interleukin-6（ IL-6）, are produced by systemic inflammation. The proinflammatory cytokines can increase muscle protein degradation, and can lead loss of appetite. The energy imbalance occurring in the patients with COPD are caused by hypermetabolism （increased energy expenditure） and loss of appetite（ deficient energy intake）. In the nutritional management of patients with COPD, high-fat diets are recommended for the aim of increasing energy intake and reducing carbon dioxide production. The energy requirements are calculated from 1.5 × resting energy expenditure （REE）. In the nutritional therapy for patients with COPD, total calories from fat are a high ratio （35-50% of total energy）. The nutritional management is selected among oral, enteral, and parenteral nutrition. The parenteral lipid emulsions are used in parenteral nutrition. The highfat enteral formulas are used in enteral nutrition. The high-fat diets are used in oral nutrition, and oral nutritional supplements （ONS） are provided for inadequate energy intake. The high-fat enteral formulas and diets are including medium-chain triglyceride （MCT） and omega-3 fatty acid. The nutritional management using lipids is efficient means for providing energy in patients with COPD.
