Inflammatory bowel disease (IBD) encompasses Crohn's disease (CD) and ulcerative colitis (UC) is a chronic, relapsing, inflammatory disorder of the digestive tract that characteristically develops in adolescence and early adulthood. IBD is associated with inflammation and negative nutrient balance, which is a risk factor for malnutrition. Multiple definitions of malnutrition have been proposed in literature. The early definitions of malnutrition referred to a state of under nutrition. Subsequently, an imbalance of nutrients, either deficiency or excess, was included in the definition. World Health Organization (WHO) defines malnutrition as deficiency, excess, or imbalance in a person's intake of energy and/or nutrients. The reported prevalence of malnutrition in IBD varies between 16 % and 75%. Several studies have reported a prevalence of weight loss in 70%-80% of hospitalized IBD patients and in 20%-40% of outpatients with CD. Several factors contribute to malnutrition in IBD patients. It is known that a reduced oral food intake is a main determinant of malnutrition in patients with IBD. Several mechanisms are involved in the reduction of food intake. Patients with active IBD often experience loss of appetite due to nausea, vomiting, abdominal pain, and diarrhea. Medications may also induce nausea, vomiting, or anorexia. Glucocorticoids often reduce phosphorus, zinc, and calcium absorption and may lead to osteoporosis. Long-term sulfasalazine therapy, a folic acid antagonist, might be related to anemia. Hospitalization itself or prolonged restrictive diet may lead to a significant reduction of food intake. The severity of malnutrition in IBD patients is dependent on the activity, duration and extent of the disease. In particular, on the magnitude of the inflammatory systemic response mediated by pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF) and interleukins-1 and -6, which can increase catabolism and lead to anorexia. Sarcopenia has been defined by the European Working Group on Sarcopenia (EWGSOP) combining low muscle strength, low muscle quantity/quality, and low physical performance. There has been a major change from the original operational definition, as low muscle strength was added as a prerequisite to definitions based only on the detection of low muscle mass. In addition, low physical performance is considered a predictor for poor outcomes; thus, such measures are useful to classify the severity of sarcopenia. Nutritional status is traditionally measured with anthropometric tests including height, weight, body mass index (BMI), body circumferences (waist, hip, and limbs), and skinfold thickness. These parameters improve with IBD treatment but may not reflect changes in body composition. The purpose of the NRS-2002 system is to detect the presence of under nutrition and the risk of developing under nutrition in the hospital setting. It contains the nutritional components of Malnutrition Universal Screening Test (MUST). In addition, a grading of severity of disease as a reflection of increased nutritional requirements. With the prototypes for severity of disease given, it is meant to cover all possible patient categories in a hospital.