Medical weight loss terminology explained (Part 2): Nutritional assessment standards and energy metabolism parameters

11. Malnutrition: A state of energy or nutrient deficiency caused by insufficient intake or impaired utilization. This leads to changes in body composition, decline in physiological and mental function, and may result in adverse clinical outcomes. Malnutrition can be determined through assessment, but there is currently no internationally unified diagnostic standard. Based on its cause, it can be divided into four types: the first type is primary malnutrition caused by starvation, which can be diagnosed as an independent disease; the second type is secondary malnutrition caused by various diseases or treatments, which is diagnosed and managed as a complication of the disease; the third type is age-related malnutrition, including sarcopenia; and the fourth type is a mixed type caused by different combinations of the above causes. 12. Index of Nutrition Quality (INQ): The index of nutrition quality is the ratio of the degree to which a food meets the body's nutritional needs (nutrient density) to the degree to which the food meets the body's energy needs (energy density). INQ is a commonly used indicator for evaluating the nutritional value of food. 13. Glycemic Index (GI): The increase in the area under the blood glucose curve over 23 hours after consuming 50g of carbohydrates compared to the fasting level, divided by the corresponding increase after consuming 50g of glucose. Generally, foods with a GI < 55% are defined as low-GI foods, those with a GI of 55% ≥ 20 are medium-GI foods, and those with a GI < 10 are low-GI foods. 15. Dietary Reference Intake (DRI): The intake of energy and specific dietary nutrients required to meet the basic nutritional needs of a healthy individual. It is a set of reference values ​​for average daily dietary nutrient intake developed based on the Recommended Dietary Allowance (RDA). 16. Recommended Daily Allowance (RDA): The recommended daily intake of nutrients to prevent nutritional deficiencies. Equivalent to the "Recommended Intake." 17. Recommended Nutrient Intake (RNI): The nutrient intake level that meets the needs of the vast majority of individuals in a specific sex, age, and physiological condition group. 18. Adequate Intake (AI): A safe intake level of a nutrient, obtained through observation or experimentation in healthy individuals. 19. Tolerable Upper Intake Level (UL): The highest average daily intake of a nutrient that can be consumed. This amount will not cause harm to almost all individuals in the general population. 20. Proposed Intakes for Preventing Non-Communicable Chronic Diseases (PI-NCD): The recommended daily intake of essential nutrients for the prevention of non-communicable chronic diseases. 21. Specific Proposed Levels (SPL): The recommended daily intake of food components other than essential nutrients for maintaining human health. 22. Acceptable Daily Intake (ADI): An estimate of the amount of a substance a human can consume daily throughout their life without producing any detectable adverse effects. It is generally expressed in mg/kg body weight. 23. Basal Metabolism: The energy metabolism of the human body under resting and isothermal conditions (generally 18-25°C), after a 12-hour fast, while lying still, relaxed, and awake. It is the minimum energy metabolism required to sustain life. Basal Metabolic Rate (BMR): The basic metabolic rate per unit of time. It represents the energy expenditure per hour per square meter of body surface area or per kilogram of body weight when the human body is in a basal metabolic state. Major factors such as age, sex, body type, body composition, and endocrine function affect its variation. It is expressed in kJ (kcal)/(m²·h). 24. Basal Energy Expenditure (BEE): The energy expenditure during 24 hours of basal metabolism, expressed in kJ (kcal)/day. 25. Resting metabolic rate (RMR) is the energy metabolism per unit time and per unit body surface area 3-4 hours after eating, under conditions of rest without skeletal muscle activity, expressed in kJ (kcal) (m²·h). 26. Resting energy expenditure (REE) is the energy expenditure of the body in 24 hours under conditions of rest without skeletal muscle activity, expressed in kJ (kcal)/day. 27. Energy metabolism is the process of energy release, transfer, utilization, and consumption during the body's metabolism. 28. Energy balance is the dynamic equilibrium between energy intake and energy expenditure. A balance is defined as energy intake and energy expenditure being approximately equal (not exceeding ±5%). A positive balance is when energy intake exceeds expenditure; a negative balance is when energy intake is less than expenditure. 29. Energy source nutrient is a nutrient that produces energy during metabolism in the body. These include carbohydrates, fats, and proteins. 30. The energy coefficient is the energy produced when one gram of energy-producing nutrient is oxidized in the body. The energy coefficients for carbohydrates, fats, and proteins are 17 kJ (4 kcal), 37 kJ (9 kcal), and 17 kJ (4 kcal), respectively.