Nutritional Assessment

Food and nutrition are basic indispensable needs of humans. Nutrition plays a critical role in maintaining the health and well-being of individuals and is also an essential component of the healthcare delivery system. The nutritional status of individuals affects the clinical outcomes. Essential nutrients are classified into six groups, namely carbohydrates, proteins, lipids, minerals, vitamins, and water. Nutritional requirements of healthy individuals depend on various factors, such as age, sex, and activity. Hence, recommended values of dietary intakes vary for each group of individuals. In the United States, the Food and Nutrition Board of the Institutes of Medicine (IOM) under the National Academy of Sciences issues nutrition recommendations for populations throughout the life span called Dietary Reference Intakes (DRIs). An imbalance in nutritional intake leads to malnutrition. The word ‘malnutrition’ is defined in multiple ways, and there is still no consensus. Traditionally, the term malnutrition has been used in the context of lack of energy intake or deficiencies of nutrients, under which two main conditions, namely marasmus, and kwashiorkor, are discussed. Marasmus primarily refers to energy or calorie deficiency, whereas kwashiorkor refers to protein deficiency characterized by peripheral edema.  However, the term malnutrition now includes conditions caused by both insufficient as well as excess intake of macronutrients and micronutrients. As per WHO guidelines, malnutrition encompasses three categories, namely, Undernutrition (low weight-for-height, low height-for-age, and low weight-for-age), Micronutrient (vitamins and minerals) deficiency or excess, and Overnutrition (overweight, obesity, and other diet-related health conditions such as type 2 diabetes mellitus, cardiovascular disorders, etc.). The presentation of malnutrition can be acute, sub-acute, or chronic and may or may not be associated with underlying inflammation. Furthermore, the double burden of malnutrition has also been emphasized in various studies. This involves the dual manifestation of overnutrition and undernutrition, which makes the diagnosis of malnutrition a challenge.  Hence, a comprehensive, multi-faceted evaluation of a patient's nutritional status is warranted. A comprehensive nutritional assessment, however, should be differentiated from nutritional screening. Nutritional screening is done to quickly identify individuals at risk of developing malnutrition.  For example, the mini nutritional assessment (MNA) is used in the geriatric patient population to screen for individuals at risk of malnutrition. This screening tool consists of a questionnaire and has a scoring system that helps identify at-risk individuals. On the other hand, a comprehensive nutritional assessment is performed to evaluate the nutritional status of patients already identified at nutritional risk. Nutritional assessment allows healthcare providers to systematically assess the overall nutritional status of patients, diagnose malnutrition, identify underlying pathologies that lead to malnutrition, and plan necessary interventions.