Chapter 7 Part 1 Energy Balance PDF

Chapter 7 Part 1 Energy Balance 1  Dietary Patterns Almost 75% of adults are overweight or obese. From early to middle adulthood, the majority of adults gain about 1.1–2.2 lb per year. 60% of adults are affected by obesity-related chronic disea...

Chapter 7 Part 1 Energy Balance 1  Dietary Patterns Almost 75% of adults are overweight or obese. From early to middle adulthood, the majority of adults gain about 1.1–2.2 lb per year. 60% of adults are affected by obesity-related chronic diseases. Most reliable and successful weight loss comes from a: commitment to lifestyle behaviors that improve dietary and physical activity patterns combination of improved energy balance, increased physical activity, and behavior modification © McGraw Hill, LLC 2  Obesity Epidemic © McGraw Hill, LLC  Obesity Epidemic - 2020 © McGraw Hill, LLC Globesity Source: CDC Behavioural Risk Factor Surveillance System. Access the text alternative for slide images. 5  Energy Balance Energy balance: The relationship between energy intake and energy expenditure 1. Energy equilibrium: When calories consumed matches the amount of energy expended 2. Positive energy balance: Energy intake exceeds energy expenditure and results in weight gain 3. Negative energy balance: Energy intake is less than energy expenditure and weight loss occurs 6  Energy Balance 2 Positive energy balance is desired during growth stages: Pregnancy Infancy Childhood Adolescence Aging does not cause weight gain. Negative energy balance is desired in adults when body fatness exceeds healthy levels. Not recommended during growth stages as it can impair normal growth pattern 7 Energy Intake Amount of energy in food or beverages can be estimated using nutrient databases or software Calorie values are derived directly by using a bomb calorimeter. Calorie content can also be calculated by determining the grams of the energy-providing macronutrients and alcohol and multiplying these compounds by their physiological values. 8 Energy Expenditure Thermogenesis Thermogenesis is a metabolic process in which the body burns calories to produce heat. The body uses energy for 3 main purposes: 1. Basal metabolism 2. Thermic Effect of Food - Digestion, absorption, and processing of ingested nutrients 3. Physical activity - variable A minor form of energy output is expended during fidgeting or shivering 9 Basal Metabolism 1 Basal metabolism (BMR) 1. Minimum amount of energy expended in fasting to keep a resting, awake body alive in a warm, quiet environment 2. Accounts for about 60 to 80% of total energy expenditure 3. Processes involved include beating of heart, respiration of lungs, and activity of other organs If a person is not fasting or rested, the resting metabolism is used (R M R). BMR and RMR are expressed as the number of calories burned per unit of time, average: Women is 0.9 kcal/kg per hour Men is 1.0 kcal/kg per hour 10 Basal metabolism (BMR) BMR peaks at one year of age and declines until age 20. BMR remains stable from ages 20 to 60. BMR declines again in older adulthood 11 Basal Metabolism 2 Factors that increase basal metabolism: Greater muscle mass Larger body surface Male gender Body temperature Higher than normal secretions of thyroid hormones Nervous system activity Growth stages Caffeine and tobacco use Recent exercise 12 Basal Metabolism 3 Factors that decrease basal metabolism: 1. Lower than normal secretions of thyroid hormones 2. Restricted calorie intake 3. Less body surface area and muscle mass 4. Aging after age 30 years 13 Energy for Physical Activity Physical activity increases energy expenditure above basal needs by 25 to 40%. Being active or inactive determines much of our total energy expenditure Climb stairs rather than take elevator Walk rather than drive Stand in a bus rather than sit The increased rate of obesity in North America is caused in part by our inactivity. 14 Thermic Effect of Food Thermic effect of food (TEF) 1. Energy used to digest, absorb, transport, store, and metabolize 2. Accounts for 5 to 10% of energy consumed 3. Influenced by food composition TEF for protein rich meals is 20 to 30% TEF for carbohydrate rich meals is 5 to 10% TEF for fat rich meal is 0 to 5% TEF for alcohol is 20% 4. Also influenced by size of meal Larger meals have higher TEF 15  Critical Thinking: T E F A few foods, such as celery, have been hypothesized to use more calories for TEF than they contain, making them a negative calorie food. Despite its recurring popularity in fad diets, there is no scientific evidence supporting the idea that any food, including celery, is calorically negative. Although celery still yields some calories, it Ingram Publishing/Getty Images remains an excellent choice to include in a healthy dietary pattern. Are celery, and other vegetables, considered a low or high energy- dense food option? © McGraw Hill, LLC 16 Adaptive Thermogenesis 1 Thermogenesis Change in the BMR in response to environmental stresses. Small contribution to total energy expenditure Produced when body expends energy for non-voluntary physical activity Triggered by extreme cold, overfeeding, trauma, starvation Activities include fidgeting, shivering, maintaining muscle tone, holding body upright 17 Adaptive Thermogenesis 2 Brown adipose tissue is a specialized form of fat tissue Newborns have higher proportion of brown fat Participates in thermogenesis Contains many capillaries and mitochondria Found in small infants and hibernating animals 18 Measuring Energy Expenditure 1 Energy used by the body can be measured by: Direct calorimetry Indirect calorimetry Energy used can be estimated based on: 1. Height 2. Weight 3. Physical activity 4. Age 19 Measuring Energy Expenditure 2 Direct calorimetry Estimates energy expenditure by measuring amount of heat released by the body About 60% of energy the body uses leaves as heat Heat release is measured by placing person in insulated chamber surrounded by layer of water Change in temperature determines amount of energy person expended 20 Measuring Energy Expenditure 3 Indirect calorimetry Involves collecting expired air Predictable relationship between body’s use of energy and amount of oxygen consumed and carbon dioxide produced Data tables can show energy costs of different exercises 21  Measuring Energy Expenditure 4 Estimated Energy Requirements (EERs) are measurements that can estimate energy needs based on: AGE = Age in years P A = Physical Activity Estimate (see table on next slide) W T = Weight in kilograms (pounds per 2.2) H T = Height in meters (inches per 39.4) Men 19 and older: EER = 662 - (9.53  AGE) + PA (15.91 WT) + (539.6  HT)  Women 19 and older: EER = 354 - (6.91 AGE) + PA (9.36  WT) + (726  HT) 22 Physical Activity (PA) Coefficient Estimates 23  Estimating Energy Requirements The following is a sample calculation for a male who is 25 years old, 5 ft 9 in. (1.75 m), and 154 lb (70 kg) and has a highly active lifestyle. His E E R is calculated as follows: EER = 662 − (9.53  25) + 1.25  (15.91 70 + 539.6  1.75) = 2997 kcal The next equation is a sample calculation for a female who is 25 years old, 5 ft 4 in. (1.62 m), and 120 lb (54.5 kg) and has an active lifestyle. Her E E R is as follows: EER = 354 − (6.91 25) + 1.27  (9.36  54.5 + 726  1.62) = 2323 kcal © McGraw Hill, LLC 24 Energy Expenditure Estimates by Age and Activity Children Sedentary → Active 2-3 years 1000 calories → 1400 calories Females Sedentary → Active 4-8 years 1200 calories → 1800 calories 9-13 1600 → 2200 14-18 1800 → 2400 19-30 2000 → 2400 31-50 1800 → 2200 51+ 1600 → 2200 Males Sedentary → Active 4-8 years 1200 calories → 2000 calories 9-13 1800 → 2600 14-18 2200 → 3200 19-30 2400 → 3000 31-50 2200 → 3000 51+ 2000 → 2800 25 Estimating Body Weight and Composition In the past, weight-for-height tables were the method used to determine if weight was healthy The focus has shifted from these tables to considering components of body weight and their relative proportions. Now recommended to evaluate: Total body fat Location of body fat Weight-related medical problems 26 Body Mass Index Weight-for-height standard Convenient Applies to both men and women Both objective and subjective Body weight (in kg) Body weight (in lb.)  703 or Height 2 (in meters) Height 2 (in inches) 27  Body Mass Index BMI Underweight: BMI