BPK 110 Human Nutrition:Current Issues Topics for Lectures 8a 1. Energy Balance 2. Energy Input and Bomb Calorimeters 3. Three Components of Total Energy Expenditure 4. Estimating your Daily Energy Needs
Learning Objectives To describe energy balance and macronutrient energy balances To understand and describe how energy contents of the 3 macronutrients are determined with a bomb calorimeter To name and describe the 3 components of human energy expenditure To complete a sample calculation of your own estimated daily energy intake need To complete an energy balance 2
1a. Energy Balance: is when Food Energy (eaten) = Energy Expended (3 parts) If Energy In = Energy Out? Body weight is stable. If Energy In > Energy Out? Body weight increases. If Energy In < Energy Out? Body weight decreases.
1b) Macronutrient Balances: Caloric Values of Energy Nutrients or Macronutrients All determined with a Bomb Calorimeter We can calculate an energy balance for each Macronutrient Macro-Nutrient or e.g. CHO in - CHO out 4 kcal/g e.g. Fat in - Fat out 9 kcal/g 4 kcal/g (kcal = 1000 cal = 1 Cal)
We measure energy in calories or Joules With a Small c 1 Calorie (Cal) = 1 kilocalorie (kcal)=1000 calories With a BIG C Energy gives the ability to do work A Calorie
2) Energy In and the Bomb Calorimeter -a Bomb Calorimeter determines amount of heat or energy a food releases when burned -food caloric or energy values are given at the DIET ANALYSIS PLUS website -gives the Energy In of the Energy Balance Equation
3) Three Components of Human Total Energy Expenditure (TEE) 25 50% physical activity 5 10% thermic effect of food 50 65%
Basal Μetabolism 50-65% of TEE -Basal Metabolic Rate (BMR) -usually measured in the a.m. -after a 12-14 hour fast -takes about 30 min to measure
Table 9-3 Factors that Affect BMR
Estimating Physical Activity Energy Expenditure from oxygen consumption during physical activity different activities have different caloric costs Appendix E in S,W &P ver 3 for different daily activities Physical Activity: on average is 25-50% of TEE
Thermic or Thermal Effect of Feeding (TEF) TEF is 5 to 10% of energy value of a meal or all food consumed each day energy cost of digestion and absorption of food estimated from oxygen consumption after a meal
4. Estimating your Daily Energy Needs: 3 steps Step 1. Calculate the Basal Metabolic Rate: Females: 0.9 kcal/kg/hour x body weight in kg Males: 1.0 kcal/kg/hour x body weight in kg -e.g. If Ms. N.R. Gee weighs 50 kg, what is her basal metabolic caloric need per day? 50 kg x 0.9 kcal/kg/hour = 45 kcal/hour 45 kcal/hour x 24 hour/day in 1080 kcal/day So, 1080 kcal of energy is needed each day for Ms. N.R. Gee s basal metabolic processes
Step 2a. Estimate energy expenditure from physical activity as a % of BMR Men Women Sedentary 25-40% 25-35% Light 50-70% 40-60% Moderate 65-80% 50-70% Heavy 90-120% 80-100% Exceptional 130-145% 110-130% Ms. N.R. Gee s basal energy requirement is 1080 kcal/day Lower Limit: 40% of 1080 = 432 kcal/day Upper Limit: 60% of 1080 = 648 kcal/day
Step 2b. Detailed Estimate energy expenditure from physical activity (optional for EE calculation) Sample Calculation on p 379 S,W&P Enter Physical Activity Factor or see App. E
Step 3. Estimate Ms. N.R. Gee s Thermic Effect of Feeding (TEF) Ms. NR Gee s Energy In is 1920 kcal of food per day And her TEF is 10% of 1920 kcal/day This gives her a TEF of 192 kcal/day Since TEF is 5-10% of caloric value of food consumed (above we chose to use 10% in the calculation)
A summary of Ms. N. R. Gee s Total Energy Expenditure (TEE): 1. Her BMR= 1080 kcal/day 2. Her Physical Activity Energy Expended = 432 to 648 kcal/day 3. Her Thermic Effect of Feeding = 192 kcal/day 4. Her TEE is between 1704 & 1920 kcal/day - 1080 kcal + 432 kcal + 192 kcal = 1704 kcal/day - 1080 kcal + 648 kcal + 192 kcal = 1920 kcal/day
Ms. N. R. Gee s Total Energy Expenditure Balance: Her TEE is between 1704 & 1920 kcal/day - 1080 kcal + 432 kcal + 192 kcal = 1704 kcal/day - 1080 kcal + 648 kcal + 192 kcal = 1920 kcal/day Her Food Intake is 1920 kcal/day Her Total Energy Balance is 1920 kcal/d -1920 kcal/d =0 Or Her Total Energy Balance is 1920 kcal/d -1704 kcal/d =+216
Summary Lecture 8a 1. Energy Balance 2. Energy Input and Bomb Calorimeters 3. Three Components of Total Energy Expenditure 4. Estimating your Daily Energy Needs