Nutrition is the "process by which substances in food are transformed into body tissues and provide energy for the full range of physical and mental activities that make up human life (Carpenter, 2016). Adequate nutrition requires that essential nutrients-including carbohydrates, proteins, fats, vitamins, minerals, and water-be ingested in appropriate amounts.
Optimal nutritional status results in more energy to meet activity demands, higher levels of immunity, and faster healing. When nutrition is not optimal, undernutrition (malnutrition) or overnutrition (overweight or obesity) occurs, both of which are associated with many diseases and disorders.
Hydration status also affects health and is assessed with nutrition. Many people do not drink enough fluids, which puts them at risk for chronic mild dehydration. Overhydration is rare in healthy individuals and is only assessed in clients who are at risk for fluid retention, such as those with kidney, liver, and cardiac diseases in which the fluid dynamic mechanisms are impaired.
Nutritional and hydration assessment helps identify the client’s overall health status and need for health promotion. It identifies risk factors for obesity, dietary deficits (malnutrition and undernutrition), dehydration, food allergies, food intolerances, and food contamination.
The most beneficial nutritional status requires a balance of nutrient intake to meet daily metabolic demands. Metabolic demands vary based on developmental level, lifestyle, and other energy demands. Optimal nutrition is often thought to be a balance of calories and exercise, but metabolic demands require a variety of nutrients and not just a focus on calories.
Dietary guidelines for Americans include:
(U.S. Department of Health and Human Services [UHHS] and U.S. Department of Agriculture [USDA], 2015, Executive Summary). (See the full report of the 2020-2025 Dietary Guidelines for Americans at https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf.)