ENERGY

• Energy


  The capacity to do work. It may exist in potential, kinetic, thermal, electrical, chemical, nuclear, or other various forms
• How humans take in and use energy

  1. Take in energy from foods and drinks (measured in Calories)

  2. Convert energy into work, heat, and storage
• Storage


  Glycogen or fat
• Activity thermogenesis (AT)


  The energy expended during active exercise such as fitness and sports exercise<|>The energy expended during activities of daily living, referred to as non-exercise activity thermogenesis - Breathing, going to the CR
• Basal Metabolic Expenditure


  The measurement of the basal metabolic rate extrapolated to 24 hours; usually expressed as kilocalories per 24 hours (kcal/24 hr)

  
• Basal Metabolic Rate (BMR)


  The energy needed to sustain the metabolic activities of cells and tissues and to maintain circulatory, respiratory, gastrointestinal, and renal processes; expressed as kilocalories per kilogram of body weight per hour; measured in the morning 10 to 12 hours after ingestion of food, drink, alcohol, or nicotine

  
• Basal Metabolic Rate - calculation


  Measured with 10 to 12 hours of sleep or an 8-hour fast
• Resting Metabolic Rate - calculation


  Measured with lesser restrictions

  
• Calorie


  The amount of energy required to raise the temperature of 1 ml of water at 15 degrees C by 1 degrees C : 15 – 16 degrees C

  
• Direct calorimetry


  A method for measuring the amount of energy expended by measuring the energy expended by monitoring the rate at which a person loses heat from the body to the environment when placed inside a structure large enough to permit moderate amounts of activity

  
• Estimated Energy Requirement (EER)


  The average dietary energy intake that is predicted to maintain energy balance in a healthy adult of a defined age, gender, weight, height, and level of physical activity consistent with good health
• NDAP - weight-based predictive equations

  Mifflin-St. Jeor's, Harris-Benedict, Krause and Mahan

  
• Predictive equations


  Utilized in the absence of direct calorimetric equipment (e.g. bomb calorimeter, respiration chamber)
• Direct and Indirect Calorimetry

  Gold standard for measuring Calorimetry
• Portable Indirect Calorimeter


  Portable
• Enteric Calorimetry


  Calorimetry method
• Metabolic equivalents (METs)


  The measure of caloric expenditure by the amount of oxygen consumed per minute per kilogram of bodyweight; 1 MET = approx. 3.5 ml oxygen consumed per kilogram of bodyweight per minute in adults
• Caloric deficit plan


  1. 1 kg BW = 7,700 kcal

  2. 75 kg - (ideal standard for weight loss) 10% BW in 6 months (7.5 kg weight loss in 6 months)

  3. Use Current bodyweight - not the IBW (due to intake suppression leading to lesser caloric intake and sudden decline of energy intake leading to possible fatigue and negative energy balance??)

  4. 7.5 kg * 7,700 kcal (per 1 kg BW) = 57,750 kcal (for 180 days) = 320.8 kcal/day (deficit)

  5. 321 kcal - PA and Diet

  6. 100 kcal - Intake Deficit (Food)

  7. 221 kcal - Physical Activity

  8. TER - 1,800 kcal - 100 kcal (intake deficit food) = 1,700 kcal (for meal planning)

  9. TER < BMR (incorrect)

  10. TER > BMR (ideal)
• Bottleneck (plateau of weight loss through controlled intake)


  Intervention: Physical Activity
• Physical Activity Level (PAL)

  The ratio of TER (Total Energy Requirement) to basal energy expenditure (BEE); PAL : TEE/BEE (ratio)

  
• PAL factors are dismissed in the case of Stress/Injury level
• Resting Metabolic Expenditure (RER)


  The energy expended for the maintenance of normal body functions and homeostasis; represents the largest portion of TER; expressed as kilocalories per kilogram of bodyweight per hour; may be as much as 10% to 20% higher than the basal metabolic rate, allowing for the energy spent as the result of the thermic effect of food (TEF) or excess postexercise oxygen consumption (EPOC)

  
• Respiratory Quotient (RQ)


  The ratio of moles of carbon dioxide produced to the moles of oxygen consumed. mol of CO2: mol of O2<|>Protein - high RQ<|>Carb - high RQ (55-75% healthy); (COPD/lung failure lessened intake of CHO - <55% CHO)<|>Fat - lowest RQ
• Thermic Effect of Food (TEF)


  The increase in energy expenditure associated with the processes of digestion, absorption, and metabolism of food; represents approximately 10% of the sum of resting metabolic expenditure and the energy expended in the physical activity and includes facultative thermogenesis and obligatory thermogenesis, often called diet-induced thermogenesis, specific dynamic action, or the specific effect of food<|>Protein - highest TEF (good for postexercise consumption - furthers ketosis and glycogenolysis (in the absence of easily absorbed nutrients - such as glucose in the form of sugars (protein shakes)))

  
• Total Energy Expenditure (TEE)


  The sum of basal energy expenditure, activity thermogenesis, and the thermic effect of food; the daily total energy expended by a person in 24 hours

  
• Components of Energy Expenditure

  • BMR
  • TEF
  • PA (Activity thermogenesis)

  
• Resting Energy Expenditure is the energy expended in the activities necessary to sustain normal body functions and homeostasis

  
• Resting Energy Expenditure


  • Includes respiration and circulation, the synthesis of organic compounds, the pumping of ions across membranes, the energy required by the CNS, and the maintenance of body temperature
• Muscle mass (low quality) - higher risk of diabetes (glycogen storage - muscles (150g) and liver (90g))
• Factors that affect REE

  • Body size
  • Body Composition
  • Age
  • Sex
  • Hormonal Status
• Body Composition


  Fat-free mass (FFM), the metabolically active tissue in the body, is a predictor of REE<|>FFM includes muscles, bones, organs, body water (both intracellular and extracellular), and minerals

  
• Methods to measure FFM

  Underwater weighing (hydrodensitometry) - measured via water displacement<|>Dual x-ray absorptiometry (DEXA) - calculation of bone density (osteoporosis diagnostic test) specific cases - (metastasized cancer stages; frailty; sarcopenia - muscle mass loss: immobility (bedridden individuals))<|>Air-displacement plethysmography (e.g. the Bod Pod)

  
• Hydrodensitometry is the most preferred method to measure FFM

  
• Age and REE


  REE is highest during periods of rapid growth (deposition - creation of cells and tissues), chiefly during the first and second years of life<|>Additional energy required for synthesizing and depositing body tissue is about kcal/g of tissue gained<|>Growing infants may store as much as 12% to 15% of the energy value of their food in the form of new tissue<|>As a child becomes older, the caloric requirement for growth is reduced to about 1% of the total energy requirement<|>After early adulthood there is a decline in RMR of 1% to 2% per kilogram of FFM per decade

  
• Sex and metabolic rates

  Women, who generally have more fat in proportion to muscle than men, have metabolic rates that are approximately 5% to 10% lower than men of the same weight and height

  
• Hormonal status and metabolic rate

  Hyperthyroidism increases energy expenditure<|>Hypothyroidism decreases energy expenditure<|>Metabolic rate of women fluctuates with the menstrual cycle, with a slight increase during the luteal phase

  
• Thermic Effect of Food (TEF)


  Also referred to as diet-induced thermogenesis (DIT), specific dynamic action (SDA), and the specific effect of food (SEF)<|>Obligatory thermogenesis is the energy required to digest, absorb, and metabolize nutrients, including the synthesis and storage of protein, fat, and carbohydrate<|>Facultative thermogenesis is the "excess" energy expended in addition to the obligatory thermogenesis and is thought to be attributable to the metabolic inefficient of the system stimulated by Sympathetic nervous activity (fight or flight response)<|>TEF is greater after the consumption of carbohydrates and proteins than after fat

  
• Factors affecting the Thermic Effect of Food

  Fat is metabolized efficiently with only 4% wastage, compared with 25% wastage when carbohydrate is converted to fat for storage<|>Consumption of cakes and pastries - excess 100g of Carbohydrates stored as fat for storage; 25% wastage urine and feces<|>Spicy foods enhance and prolong the effect of TER

  
• Activity thermogenesis


  Activity thermogenesis (AT) is the energy expended during sports or fitness exercise<|>Nonexercise activity thermogenesis (NEAT) is the energy expended during activities of daily living<|>The contribution of physical activity is the most variable component of TEE, which may be as low as 100 kilocalories (kcal)/day in sedentary people or as high as 3000kcal/day in very active people<|>AT tends to decrease with age, a trend that is associated with a decline in FFM (fat-free mass) and an increase in fat mass
• Direct Calorimetry


  The measurement of the amount of heat produced by a patient while housed for a certain amount of time within a small chamber<|>Based on the first law of thermodynamics and the assumptions of thermal stability and low energy storage capacity, that energy spent in physiological processes is ultimately dissipated as heat and thus total energy expenditure can be assessed directly measuring heat production