Energy Chapter 2 © 2004, 2002 Elsevier Inc. All rights reserved.

Energy n Capacity to do work n Derived from the sun—photosynthesis in plants n Humans consume plants and animal flesh, thus benefiting from energy sources n Capacity to do work n Derived from the sun—photosynthesis in plants n Humans consume plants and animal flesh, thus benefiting from energy sources

© 2004, 2002 Elsevier Inc. All rights reserved. Energy Expenditure n Resting energy expenditure (REE) n Thermic effect of food (TEF) n Activity expenditure n Resting energy expenditure (REE) n Thermic effect of food (TEF) n Activity expenditure

© 2004, 2002 Elsevier Inc. All rights reserved. Factors Affecting REE n Body size n Body composition n Age n Sex n Hormonal status n Fever n Extreme environmental temperatures n Body size n Body composition n Age n Sex n Hormonal status n Fever n Extreme environmental temperatures

© 2004, 2002 Elsevier Inc. All rights reserved. Energy Expenditure n Basal energy expenditure (BEE) n Minimal energy compatible with life n Energy used over 24 hours n 60% to 70% of total energy expenditure (TEE) n Basal energy expenditure (BEE) n Minimal energy compatible with life n Energy used over 24 hours n 60% to 70% of total energy expenditure (TEE)

© 2004, 2002 Elsevier Inc. All rights reserved. Energy Expenditure of Organs in Human Adults

© 2004, 2002 Elsevier Inc. All rights reserved. Dual-Energy X-Ray Absorptiometry Courtesy The Dunn Nutrition Centre, University of Cambridge, Cambridge, England.

© 2004, 2002 Elsevier Inc. All rights reserved. The Effect of Adding Spices to a Meal on the Resting Metabolic Rate (RMR) of Healthy Subjects (From McCrory P. et al. Energy balance, food intake and obesity. In: Hills AP, Wahlqvist ML [eds.]. Exercise and Obesity. London: Smith-Gordon and Co., Ltd., 1994.)

© 2004, 2002 Elsevier Inc. All rights reserved. Estimating Energy Requirements n Each method for calculating energy needs differs and has limitations, so remember that they are only estimates of energy requirements.

© 2004, 2002 Elsevier Inc. All rights reserved. Units of Energy Measurement n Kilocalorie (kcal) —Carbohydrate = 4 kcal/g —Protein = 4 kcal/g —Fat = 9 kcal/g n Kilojoule (kJ)—non–US countries; the metric value —Carbohydrate = 17 kJ —Protein = 17kJ —Fat = 38 kJ n Kilocalorie (kcal) —Carbohydrate = 4 kcal/g —Protein = 4 kcal/g —Fat = 9 kcal/g n Kilojoule (kJ)—non–US countries; the metric value —Carbohydrate = 17 kJ —Protein = 17kJ —Fat = 38 kJ

© 2004, 2002 Elsevier Inc. All rights reserved. Measuring Energy Expenditure n Direct calorimetry n Indirect calorimetry n Doubly labeled water n Direct calorimetry n Indirect calorimetry n Doubly labeled water

© 2004, 2002 Elsevier Inc. All rights reserved. Factors for Physical Activity Levels (PAL) Based on Doubly Labeled Water (DLW) Studies (Adapted from Shetty PS, et al. Energy requirements of adults: An update on basal metabolic rates (BMRs) and physical activity levels (PALs). Eur J Clin Nutr 50 (suppl 1): S11, 1996.)

© 2004, 2002 Elsevier Inc. All rights reserved. Energy Value of Food