It has long been recognized that malnutrition changes physical appearance, as evidenced by muscle wasting, losses of fat stores, signs of vitamin and mineral deficiencies, and reduced physical activity. Malnutrition is associated with poor clinical outcomes and quality of life. Various nutrition assessment parameters have been used to determine the presence and degree of malnutrition, including use of anthropometric measurements and laboratory values. In the mid-1980s, the Subjective Global Assessment (SGA) tool was developed in acknowledgement of the physical features of malnutrition; an evaluation of muscle mass, fat stores, edema, and functional capacity was a major component of the SGA. SGA became a gold standard for nutrition assessment. Since then, nutrition assessment evolved from anthropometric tools and laboratory values to one based on the nutrition-focused physical examination (NFPE). NFPE uses a head-to-toe approach to evaluate muscle mass, fat stores, fluid retention, micronutrient deficiencies, and functional capacity. In 2012, the Academy of Nutrition and Dietetics and the American Society for Parenteral and Enteral Nutrition (AND/ASPEN) developed a standardized definition for malnutrition diagnoses for coding and reimbursement; the AND/ASPEN malnutrition diagnosis is derived from the SGA. A few studies demonstrated good agreement between SGA and AND/ASPEN malnutrition criteria in diagnosing malnutrition, and some studies have shown malnutrition, as diagnosed by AND/ASPEN criteria, is associated with poor clinical outcomes. More research is needed to validate the AND/ASPEN malnutrition diagnosis criteria.