PURPOSE OF REVIEW: Chronic obstructive pulmonary disease is the fifth leading cause of mortality in the world. This study reviews diet as a risk or protective factor for chronic obstructive pulmonary disease, mechanisms of malnutrition, undernutrition consequences on body functioning and how to modulate nutritional status of patients with chronic obstructive pulmonary disease. RECENT FINDINGS: Different dietary factors (dietary pattern, foods, nutrients) have been associated with chronic obstructive pulmonary disease and the course of the disease. Mechanical disadvantage, energy imbalance, disuse muscle atrophy, hypoxemia, systemic inflammation and oxidative stress have been reported to cause systemic consequences such as cachexia and compromise whole body functioning. Nutritional intervention makes it possible to modify the natural course of the disease provided that it is included in respiratory rehabilitation combining bronchodilators optimization, infection control, exercise and, in some patients, correction of hypogonadism. SUMMARY: Diet, as a modifiable risk factor, appears more as an option to prevent and modify the course of chronic obstructive pulmonary disease. Reduction of mechanical disadvantage, physical training and anabolic agents should be used conjointly with oral nutrition supplements to overcome undernutrition and might change the prognosis of the disease in some cases. Major research challenges address the role of systemic inflammation and the best interventions for controlling it besides smoking cessation.