Porth's Essentials of Pathophysiology, 4e

utritional status describes the condition of the body related to the availability and use of nutrients. Nutrients that are taken into the body can be used to provide the energy needed to perform various body func- tions or they can be stored for future use. The stability of body weight and composition of lean-to-fat tissue ratio over time requires that a person’s energy intake is bal- anced with energy expenditure. Also, because different foods contain different amounts of proteins, fats, carbo- hydrates, vitamins, and minerals, appropriate amounts of these nutrients must be maintained to ensure that the body’s metabolic systems are adequately supplied. This chapter discusses nutritional status, overnutrition and obesity, and undernutrition and eating disorders. The nutrients from the foods we eat are used by cells to provide the body with the energy needed to perform almost all cellular functions. Energy is measured in heat units called calories . A calorie, spelled with a small “c” and also called a gram calorie , is the amount of heat or energy required to raise the temperature of 1 g of water by 1°C. A kilocalorie (kcal), or large calorie (abbrevi- ated as a capital C), is the amount of energy needed to raise the temperature of 1 kg of water by 1°C. Because a calorie is so small, kilocalories often are used in nutri- tional and physiologic studies. Energy Metabolism Metabolism is the organized process through which nutrients—carbohydrates, fats, and proteins—are bro- ken down, transformed, or otherwise converted into cellular energy. The oxidation of carbohydrates and proteins provides 4 kcal/g, whereas fats yield 9 kcal/g. 1 The process of metabolism is unique in that it enables the continual release of energy, and it couples this energy with physiologic functioning. For example, the energy Disorders of Nutritional Status 10 C h a p t e r Energetics and Nutritional Status N

Energetics and Nutritional Status Energy Metabolism Nutritional Status Dietary Reference Intakes Calories

Proteins, Fats, and Carbohydrates Vitamins and Minerals Fiber Regulation of Food Intake Hunger, Appetite, and Satiety Regulatory Mechanisms Assessment of Energy Stores and Nutritional Status Anthropometric Measurements Laboratory Studies Overweight and Obesity Causes of Overweight and Obesity Adipose Tissue Adipose Tissue as an Endocrine Organ Adipose Tissue and the Inflammatory Process Types of Obesity Prevention and Treatment of Obesity Childhood Obesity Undernutrition and Eating Disorders Malnutrition and Starvation Protein-Energy Malnutrition Malnutrition in Trauma and Illness

Diagnosis Treatment Eating Disorders

Anorexia Nervosa Bulimia Nervosa Binge-Eating Disorder

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