عامر جاسم. م.م Lec.2. Theory. Nutrition Lec.2. Theory. Nutrition Nutrition is the study of how food nourishes the body. Nutrients are specific biochemical substances used by the body for growth, development, activity, reproduction, lactation, health maintenance, and recovery from illness or injury. Summary of digestive system anatomy/organ function Metabolic Requirements Basal metabolism is the energy required to carry on the involuntary activities of the body at rest—the energy needed to sustain the metabolic activities of cells and tissues. 1 عامر جاسم. م.م Lec.2. Theory. Nutrition Metabolic Activities Include: 1. Maintaining body temperature andmuscle tone. 2. Producing and releasing secretions. 3. Propelling food through the gastrointestinal (GI) tract. 4. Inflating the lungs. 5. Contracting the heartmuscle. As the amount of energy used on physical activity declines, the proportion of calories used for basal metabolism increases; it accounts for more than half of most people’s total energy requirements. Because of their larger muscle mass, men have a higher basal metabolic rate (BMR) than women. BMR is about 1 cal/kg of body weight per hour for men and 0.9 cal/kg per hour for women. Factors that Increase BMR include: 1. Growth. 2. Infections. 3. Fever. 4. Emotional tension. 5. Extreme environmental temperatures. 6. Elevated levels of certain hormones, especially epinephrine and thyroid hormones. 7. Aging, prolonged fasting, and sleep all decrease BMR. 8. Most nutritionists agree that fasting or following a very–low-calorie diet defeats a weight loss plan because the body interprets this eating pattern as starvation and compensates by slowing down the resting metabolic rate, making it even more difficult to lose weight. Body Weight Standards Ideal body weight (IBW) or healthy body weight is an estimate of optimal weight for optimal health. A general guideline, often called the rule-of- thumb method, determines ideal weight based on height. Establish Ideal Body Weight Include Body Mass Index (BMI) Using Kilograms and Meters: BMI guidelines: BMI below 18.5 is underweight BMI between 18.5 and 25 indicates an ideal weight. 2 عامر جاسم. م.م Lec.2. Theory. Nutrition BMI of 25 to 29.9 indicates an overweight individual. BMI of 30 or greater indicates obesity. BMI of 40 or greater indicates extreme obesity. Calculate The Percent of Weight Change: Weight loss is considered significant if it falls into the following guidelines: 1% to 2% in 1 week 5% in 1 month 7.5% in 3 months 10% in 6 months Waist circumference Waist circumference is measured by placing a measuring tape snugly round the patient’s waist at the level of the umbilicus. This measurement is a good indicator of abdominal fat. Where excess body fat is deposited is thought to be an important and reliable indicator of risk for disease, such as type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease. The risk increases with a waist measurement of over 40 inches in men and 35 inches in women. 3 عامر جاسم. م.م Lec.2. Theory. Nutrition Caloric Requirements After calorie requirements have been determined, adjustments can be made for weight gain or loss, as needed. For instance, (0.45 kg) of body fat equals about 3,500 cal. Therefore, to gain or lose (0.45 kg) in a week, daily calorie intake should be increased or decreased, respectively, by 500 cal (3,500 cal divided by 7 days=500 cal/d). Similarly, a weight gain or loss of (0.9 kg) per week would require an adjustment of 1,000 cal/d. Because it becomes increasingly difficult to plan an adequate diet as the calorie level drops, diets that result in more than a (0.9-kg) weight loss per week are not recommended. Energy Nutrients Carbohydrates, protein, and fats are potential sources of energy for the body Carbohydrates: commonly known as sugars and starches, are organic compounds composed of carbon, hydrogen, and oxygen. They serve as the structural framework of plants. The only animal source of carbohydrate in the diet is lactose, or ―milk sugar.‖ Protein: Protein is a vital component of every living cell. Within the human body, more than 1,000 different proteins are made by combining various amounts and proportions. Fats: Fats in the diet, or lipids, are insoluble in water and, therefore, insoluble in blood. Ninety-five percent of the lipids in the diet are in the form of triglycerides. 4 عامر جاسم. م.م Lec.2. Theory. Nutrition Factors Affecting Nutrition a. Physiologic and Physical Requirements Factors That Influence Nutrient 1. Developmental Considerations: Age influences not only nutrient requirements, but also food intake 2. Gender: Their larger muscle mass translates into higher caloric and protein requirements (therefore, slightly higher needs for B vitamins that metabolize calories and protein) because muscle is more metabolically active than adipose tissue. 3. State of Health: The alteration in nutrient requirements that results from illness and trauma varies with the intensity and duration of the stress. For instance, fevers increase the need for calories and water. b. Physical, Sociocultural, and Psychosocial Factors That Influence Food Choices 1. Economic Factors. 2. Religion. 3. Meaning of Food. 4. Culture. Nursing Diagnosing Imbalanced Nutrition as the Problem Data that the nurse collects may lead to the development of several nursing diagnoses related to nutrition: 1. Imbalanced Nutrition Less Than Body Requirements: related to nothing by mouth (NPO), inadequate tube feeding, prolonged use of a clear liquid diet, numerous food intolerance or allergies. 2. Imbalanced Nutrition More Than Body Requirements: related to overeating, inactivity, metabolic and endocrine disorders, inappropriate use of supplements Nursing Intervention 1. Providing proper and adequate nourishment to the patient is a team effort implemented in a variety of settings. 2. Diet orders are written by the physician in the inpatient setting, confirmed by the dietitian, and frequently explained to the patient by the nurse. 3. The nurse may also be responsible for screening patients at home who are at nutritional risk. 4. Observing intake and appetite. 5. Evaluating the patient’s tolerance. 6. Assisting the patient with eating. 7. Administering enteral and parenteral feedings. 8. Consulting with the dietitian and physician when dietary problems arise, addressing the potential for drug–nutrient reactions. 5