Chapter 7 Energy Balance and Weight Management

America’s Expanding Waistline Copyright 2010, John Wiley & Sons, Inc. 2

Weight Management Terms Overweight is being too heavy for one’s height or having a BMI of 25–29. Obesity is characterized by excess body fat or a BMI over 30. Copyright 2010, John Wiley & Sons, Inc. 3

BMI (Body Mass Index) Calculate BMI, where do you fall? Copyright 2010, John Wiley & Sons, Inc. 4

Copyright 2010, John Wiley & Sons, Inc. BMI and Disease Risk Copyright 2010, John Wiley & Sons, Inc. 5

Determining Who Should Lose Weight Evaluate high BMIs. (Is higher BMI due to muscle mass or fat?) Assess medical risk factors. Copyright 2010, John Wiley & Sons, Inc. 6

Copyright 2010, John Wiley & Sons, Inc. Which statement about obesity is true?   Obesity rates have remained constant over the last 15 years Obesity is defined as having a BMI over 25 Obesity rates are constant across racial and ethnic groups Obesity is defined as having a BMI over 30 d Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Energy Balance Energy balance occurs when energy consumed equals energy expenditure. Energy is measured in kilocalories (kcal, kcalories) or kilojoules (kjoules, kJ). A kcalorie is a measure of the amount of energy that is supplied to or expended by the body. Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. As food molecules are broken down, the energy in the chemical bonds of carbohydrates, proteins and fats are converted to:   a) electrical energy b) carbon dioxide c) ATP d) electrons c Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Body Energy When weight loss occurs, body energy stores are used. When weight gain occurs, body energy stores are built. Copyright 2010, John Wiley & Sons, Inc. 10

Estimating the Energy Content of Food Copyright 2010, John Wiley & Sons, Inc. 11

Stored Energy in the Body How many days can you go on, just burning through your energy stores? 2000 calories a day? Copyright 2010, John Wiley & Sons, Inc. 12

Copyright 2010, John Wiley & Sons, Inc. Primarily, energy is stored in the body as ___________ and ____________.   glycogen, triglycerides glucose, triglycerides muscle, glycogen protein, glucose a Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Body Energy There is a hierarchy of nutrient use for energy: However, everything can be converted to adipose for storage Copyright 2010, John Wiley & Sons, Inc. 14

Copyright 2010, John Wiley & Sons, Inc. Energy Terms TEE: Total energy expenditure: sum of energy for basal metabolism, activity, processing foods, deposition of new tissue Basal metabolism (60-70% of total energy expenditure) BMR: Basal metabolic rate: rate energy used for basic functions. Measured in the morning RMR: Resting metabolic rate. BMR measured after 5 hours of fasting and resting REE: Resting energy expenditure. Same as RMR Lean body mass TEF: Thermic effect of food or diet-induced thermogenesis: breaking down and storage of the food. 10% of daily intake. Pg 265 Copyright 2010, John Wiley & Sons, Inc. 15

Copyright 2010, John Wiley & Sons, Inc. Which of the following would NOT result in an increase in an individual's basal metabolic rate (BMR)?   aging past 70 an increase in muscle mass increase in body weight running a fever a Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. The energy expended to digest and store nutrients is called:   a) basal metabolic rate (BMR) b) resting energy expenditure (REE) c) resting metabolic rate (RMR) d) thermic effect of food (TEF) d Copyright 2010, John Wiley & Sons, Inc.

Measuring Energy Expenditure Energy expenditure can be measured with: Direct calorimetry: amount of heat given off Indirect calorimetry: O2 breathed in vs CO2 breathed out. Doubly-labeled water: person is given water with labeled isotopes of hydrogen and oxygen. The rate at wich both leave is measured. ? Copyright 2010, John Wiley & Sons, Inc. 18

Copyright 2010, John Wiley & Sons, Inc. Indirect calorimetry measures ____________ and ____________ to estimate calorie expenditure in humans.   food consumed; heat produced food consumed; water excreted oxygen consumed; carbon dioxide expired oxygen consumed; sweat produced c Copyright 2010, John Wiley & Sons, Inc.

Volunteer to know your estimated energy expenditure We’ll need your age, activity level, weight, etc Copyright 2010, John Wiley & Sons, Inc.

Intensity of Different Activities Copyright 2010, John Wiley & Sons, Inc. 21

Determining Physical Activity Values PA Copyright 2010, John Wiley & Sons, Inc. 22

Copyright 2010, John Wiley & Sons, Inc. Calculating Your EER Estimated energy requirement To have your EER calculated automatically: www.cspinet.org/nah/09_03/calorie_calc.html/ Copyright 2010, John Wiley & Sons, Inc. 23

What are the risks associated with obesity? Copyright 2010, John Wiley & Sons, Inc.

Excess Body Fat and Disease Risk Copyright 2010, John Wiley & Sons, Inc. 25

Methods for Assessing Body Composition Bioelectric impedance analysis: different tissues have different resistance to electric current (fat is a poor conductor of electricity) Skinfold thickness Underwater weighing (weight on land and in water helps determine the density) Dilution methods: uses water soluble isotope Radiologic methods: CT, DCA, MRI ? Copyright 2010, John Wiley & Sons, Inc. 26

Long term Regulation of Body Fat: Leptin Leptin is a protein hormone produced by adiposites signaling information about body fat. Insulin and leptin are the two important hormones. Insulin interacts to reduce food intake (it is a resting state hormone) also influences leptin levels. When fat stores are high, leptin works in the brain to reduce in take and burn up stores. Not useful to us during weight loss. (reduce satiety and supress pathways for burning fat) Copyright 2010, John Wiley & Sons, Inc. 27

Copyright 2010, John Wiley & Sons, Inc. Ryan would like to lose some weight. His energy needs are 2400 kcalories a day. If he eats about 1900 kcalories every day, in four weeks approximately how much weight will Ryan have lost due to changes in his diet? (1 lb equates to 3500 calories)   2 pounds 4 pounds 9 pounds 12 pounds B A good level of weight loss is 0.5-2lb / week Copyright 2010, John Wiley & Sons, Inc.

Contributing Factors for Obesity Inheriting a thrifty metabolism more efficient with their energy production and storage) Adaptive thermogenesis (change is metabolism brought about by changes in food intake and ambient temp, etc) overweight people may not have the increase in BMR that they should when overeating and the decrease in BMR is very high when trying to lose weight….. Futile cycling Oppposing biochemical reactions occuring at once Brown adipose tissue This adipose wastes ATP as heat (stimulated by leptin) P 287 Copyright 2010, John Wiley & Sons, Inc. 29

Tips for Shifting Energy Balance Toward Weight Loss How many of these do you do? Copyright 2010, John Wiley & Sons, Inc. 30

Tips for Shifting Energy Balance Toward Weight Loss How many of these do you do? Copyright 2010, John Wiley & Sons, Inc. 31

Copyright 2010, John Wiley & Sons, Inc. Class excercise Break into groups and design a healthy plan for weight loss for me…. Copyright 2010, John Wiley & Sons, Inc.

Extra credit: personal requirements Calculate the following values for yourself Protein requirements Total calories you need per day BMI [body mass index] EER [estimated energy requirement] Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Which guideline about weight loss is correct?    A all individuals with a BMI over 25 should lose weight  B if a child is obese, the weight should be lost as quickly as possible so it doesn't interfere with development  C most people can reduce health risks with a 5-15% weight loss  D the health benefits of weight loss do not begin to accrue until normal weight is achieved Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. A higher incidence of heart disease, high blood pressure, stroke and diabetes is associated with?    A fat on hips and thighs  B subcutaneous fat  C visceral fat  D any fat, no matter where on the body it is deposited Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Evaluating Weight-Loss Programs: how do you tell healthy diets from fad diets? Copyright 2010, John Wiley & Sons, Inc. 36

Copyright 2010, John Wiley & Sons, Inc. Which of these is important when selecting a weight loss program for long-term weight loss    A Does the program require purchase of special foods?  B Does the program offer social support?  C Does the program incorporate and encourage physical activity?  D Is there a book available which explains the diet? A,b,c Copyright 2010, John Wiley & Sons, Inc.

Pros and Cons of Some Commercial Weight-Loss Diets Safe? Effective? Inexpensive? Over the counter diet drinks: low adherence Lo cal diets (high protein): can have se such as potassium imbalance, etc. no more effective long term than others Low fat: low fat food is not low in calories. Low carb diets: low in fruits/ veggies, vitamins, high in fat and cholesterol Copyright 2010, John Wiley & Sons, Inc. 38

Copyright 2010, John Wiley & Sons, Inc. Very Low Kcalorie Diets   a) contain fewer than 1500 Kcalories per day b) cause a rapid initial weight loss c) increase metabolism d) are more effective than other diets in the long term B, contain fewer than 800 calories per day (high protein, little energy0 Copyright 2010, John Wiley & Sons, Inc.

Pros and Cons of Some Commercial Weight-Loss Diets Copyright 2010, John Wiley & Sons, Inc. 40

Common Weight-Loss Supplements Copyright 2010, John Wiley & Sons, Inc. 41

Common Weight-Loss Supplements Copyright 2010, John Wiley & Sons, Inc. 42

Copyright 2010, John Wiley & Sons, Inc. Bariatric Surgery Sometimes recommended for individuals with BMIs of 35 or greater. Gastroplasty: sometimes called “stomach stapling” or “banding” Gastric bypass: restricts the size of the stomach and bypasses part of the small intestine Copyright 2010, John Wiley & Sons, Inc. 43

Gastric Bypass Surgery Copyright 2010, John Wiley & Sons, Inc. 44

Copyright 2010, John Wiley & Sons, Inc. Chapter 7 Copyright 2010 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein. . Copyright 2010, John Wiley & Sons, Inc. 45