USE OF THE ENERGY NUTRIENTS: METABOLISM AND BALANCE CHAPTER 7 Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.2 Metabolism Two major reactions in metabolic activity Two major reactions in metabolic activity Anabolism Anabolism Process requires energy to build substances that make up the body itself and other substances necessary for body functions Process requires energy to build substances that make up the body itself and other substances necessary for body functions Catabolism Catabolism Fat oxidation Fat oxidation Krebs cycle Krebs cycle From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.3 Metabolism Role of the liver Role of the liver Regulatory role controlling the kinds and quantities of nutrients in bloodstream Regulatory role controlling the kinds and quantities of nutrients in bloodstream Detoxifies drugs Detoxifies drugs Role of the kidneys Role of the kidneys Removes waste products from the blood Removes waste products from the blood Controls many nutrients (e.g., glucose, amino acids, water) in the blood Controls many nutrients (e.g., glucose, amino acids, water) in the blood From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.4 Carbohydrate Metabolism Liver closely monitors glucose level Liver closely monitors glucose level Hyperglycemia: high blood glucose Hyperglycemia: high blood glucose Hypoglycemia: low blood glucose Hypoglycemia: low blood glucose From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.5 Protein Metabolism Amino acids (AAs) are transported through portal vein to liver Amino acids (AAs) are transported through portal vein to liver The liver is an “aminostat” monitoring intake and breakdown of AAs The liver is an “aminostat” monitoring intake and breakdown of AAs Constant dynamic state between anabolism and catabolism Constant dynamic state between anabolism and catabolism Anabolism Anabolism Utilizes an “amino acid metabolic pool” (70 g of AA) to maintain equilibrium Utilizes an “amino acid metabolic pool” (70 g of AA) to maintain equilibrium Catabolism Catabolism Occurs in liver, muscle, and kidney, creating urea as a waste product Occurs in liver, muscle, and kidney, creating urea as a waste product From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.6 Lipid Metabolism Liver regulates fat metabolism Liver regulates fat metabolism Lipogenesis converts glucose to fat Lipogenesis converts glucose to fat Lipolysis breaks down fat Lipolysis breaks down fat Oxidation process of hydrolyzing triglycerides to enter Krebs cycle for energy production Oxidation process of hydrolyzing triglycerides to enter Krebs cycle for energy production From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.7 Alcohol Metabolism Alcohol, although considered a drug or toxin, supplies kilocalories for the body to use for energy Alcohol, although considered a drug or toxin, supplies kilocalories for the body to use for energy Metabolized by the liver Metabolized by the liver Alcohol has a marked effect on blood Alcohol has a marked effect on blood pressure and risk of hypertension Alcohol promptly appears in the bloodstream and is oxidized at a rate determined by concentration & activity of liver enzymes Alcohol promptly appears in the bloodstream and is oxidized at a rate determined by concentration & activity of liver enzymes Energy value of alcohol~ approx 7 kcal/g Energy value of alcohol~ approx 7 kcal/g Those who abuse alcohol often at risk for poor nutrition Those who abuse alcohol often at risk for poor nutrition

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.8 Metabolic Interrelationships Excessive intake of any nutrient (protein, carbohydrate, alcohol, fat) results in excess energy being stored as adipose tissue Excessive intake of any nutrient (protein, carbohydrate, alcohol, fat) results in excess energy being stored as adipose tissue Images from the National Institutes of Health.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.9 Metabolic Energy Potential energy value of foods is measured in terms of kilocalories or calories Potential energy value of foods is measured in terms of kilocalories or calories Energy production: metabolism of nutrients in the Krebs cycle results in adenosine triphosphate (ATP) production Energy production: metabolism of nutrients in the Krebs cycle results in adenosine triphosphate (ATP) production From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.10 Metabolic Energy Basal metabolic rate (BMR) Basal metabolic rate (BMR) Energy required for involuntary physiological functions to maintain life, including respiration, circulation, maintenance of muscle tone, and body temperature Energy required for involuntary physiological functions to maintain life, including respiration, circulation, maintenance of muscle tone, and body temperature From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.11 Basal Metabolic Rate Factors affecting BMR Factors affecting BMR Sleep Sleep Age Age Pregnancy & lactation Pregnancy & lactation Surface area Surface area State of health State of health Body composition, gender Body composition, gender Endocrine glands: chemical Endocrine glands: chemicalmessengers Temperature Temperature Fasting & starvation Fasting & starvation From Guyton AC, Hall JE: Textbook of Medical Physiology, ed 12. Philadelphia: Saunders, 2011.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.12 Total Energy Requirement Basal energy expenditure (BEE) Basal energy expenditure (BEE) Kcal to maintain BMR + additional kcal needed for thermic effect, voluntary activities, and any increased needs from catabolic (disease states, fever) or anabolic (growth, pregnancy) processes for 24-hr period Kcal to maintain BMR + additional kcal needed for thermic effect, voluntary activities, and any increased needs from catabolic (disease states, fever) or anabolic (growth, pregnancy) processes for 24-hr period Thermic effect of food Thermic effect of food Voluntary work and play Voluntary work and play 20% to 30% of daily energy needs 20% to 30% of daily energy needs

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.13 Total Energy Requirement Estimated energy requirements (EERs) Estimated energy requirements (EERs) Kcal intake needed to maintain energy balance in healthy individuals based on specific age, gender, weight, height, and level of physical activity Kcal intake needed to maintain energy balance in healthy individuals based on specific age, gender, weight, height, and level of physical activity Levels recommended to Levels recommended to sustain body weights in desired range (BMI from 18.5 to 25 kg/m 2 ) for good health Institute of Medicine (IOM) suggests Institute of Medicine (IOM) suggests BMI approx 22 kg/m 2 to allow for a moderate weight gain in midlife without exceeding 25 kg/m 2 threshold From Mahan LK, Escott-Stump S: Krause’s Food & Nutrition Therapy, ed 13. St. Louis: Saunders, 2012.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.14 Total Energy Requirement Physical activity recommendations Physical activity recommendations Achieve physical fitness by including cardiovascular conditioning, stretching exercises for flexibility, and resistance exercises or calisthenics for muscle strength and endurance Achieve physical fitness by including cardiovascular conditioning, stretching exercises for flexibility, and resistance exercises or calisthenics for muscle strength and endurance To move toward a healthier weight and prevent weight gain, aim for about 60 minutes of moderate to vigorous intensity physical activity on most days To move toward a healthier weight and prevent weight gain, aim for about 60 minutes of moderate to vigorous intensity physical activity on most days For those who have lost weight, 60 to 90 minutes/day may be needed to maintain weight loss For those who have lost weight, 60 to 90 minutes/day may be needed to maintain weight loss

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.15 Energy Balance Proper energy balance for stable weight is maintained when the caloric intake equals the amount of energy needed for body processes and physical activity Proper energy balance for stable weight is maintained when the caloric intake equals the amount of energy needed for body processes and physical activity Factors affecting energy Factors affecting energybalance Physiological factors affecting Physiological factors affectinghunger CNS (hypothalamus) CNS (hypothalamus) Distention of stomach Distention of stomach Fat in duodenum Fat in duodenum Hormonal secretions (ghrelin, Hormonal secretions (ghrelin, leptin, serotonin) From Patton KT, Thibodeau GA: Anatomy & Physiology, ed 8. St. Louis: Mosby, 2013.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.16 Energy Balance Psychological factors Psychological factors Energy expenditure Energy expenditure Genetics may affect BMR Genetics may affect BMR Inadequate energy intake Inadequate energy intake Deficit may affect growth Deficit may affect growth Starvation may lead to malnutrition Starvation may lead to malnutrition and a vicious downward spiral in which metabolic imbalances decrease hunger and may become life- threatening without proper treatment From Guyton AC, Hall JE: Textbook of Medical Physiology, ed 12. Philadelphia: Saunders, 2011.

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc.17 Dental Hygiene Considerations To maintain body weight in healthy range, balance calories from foods and beverages with calories expended, and focus on a healthy BMI To maintain body weight in healthy range, balance calories from foods and beverages with calories expended, and focus on a healthy BMI Choose nutrient-dense foods in each group to minimize discretionary calories, including added sugars Choose nutrient-dense foods in each group to minimize discretionary calories, including added sugars Focus on amount eaten; watch portion sizes! Focus on amount eaten; watch portion sizes! Follow progress by tracking food intake and physical activity (could also include oral self-care) Follow progress by tracking food intake and physical activity (could also include oral self-care) Get moving! Physical activity can help reach and keep a healthier weight Get moving! Physical activity can help reach and keep a healthier weight

Copyright © 2015, 2010, 2005, 1998 by Saunders, an imprint of Elsevier Inc. HEALTH APPLICATION Diabetes Mellitus Discuss differences between Type I and Type II diabetes Discuss differences between Type I and Type II diabetes What ethnic groups are being impacted at the highest rates? What ethnic groups are being impacted at the highest rates? Discuss what are the best treatment interventions of the various types, and WHY? Discuss what are the best treatment interventions of the various types, and WHY? What other chronic diseases are associated with diabetes? Why are these important to overall patient health? What other chronic diseases are associated with diabetes? Why are these important to overall patient health? 18