The relationship between nutrition and inflammatory bowel disease (IBD) is a complex one, the evaluation and correction of nutritional deficits being integral part of therapy in these patients. The diet that consists in excessive consumption of meat, sugar, fats (with a higher 0 6 /o) 3 polyunsaturated fatty acids ratio) are factors involved in the epidemiology and pathogenesis of IBD. Malnutrition is present among most IBD patients, being the result of multiple mechanisms from digestive symptoms to inflammatory process, intestinal resection and administration of medications. Oral diet is high-calorie, high protein at correcting the vitamin and mineral deficiencies. Enteral diet has both an adjuvant role and that of inducing and maintaining remission as single treatment, particularly in children. Parenteral nutrition is reserved for patients with obstruction, fistula, toxic megacolon, short bowel syndrome, severe malabsorption, and other conditions that make enteral nutrition impossible or inefficient.