chapter 7 energy balance and weight management. copyright 2010, john wiley & sons, inc....

Chapter 7Energy Balance and Weight Management

Copyright 2010, John Wiley & Sons, Inc.

America’s Expanding Waistline


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.


BMI (Body Mass Index)

Calculate BMI, where do you fall?


BMI and Disease Risk


Determining Who Should Lose Weight Evaluate high BMIs. (Is higher BMI due to

muscle mass or fat?)

Assess medical risk factors.


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

Energy Balance

Energy balance occurs when energy consumed equals energy expenditure.

Energy is measured in kilocalories (kcal, kcalories) or kilojoules (kjoules, kJ).



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


Body Energy

When weight loss occurs, body energy stores are used.

When weight gain occurs, body energy stores are built.


Estimating the Energy Content of Food


Stored Energy in the Body


Primarily, energy is stored in the body as ___________ and ____________.

glycogen, triglycerides

glucose, triglycerides

muscle, glycogen

protein, glucose


Body Energy

There is a hierarchy of nutrient use for energy:


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.


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


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)


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.


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

Volunteer to know your estimated energy expenditure We’ll need your age, activity level, weight, etc



Intensity of Different Activities


Determining Physical Activity Values


Calculating Your EER

To have your EER calculated automatically:

www.cspinet.org/nah/09_03/calorie_calc.html/

What are the risks associated with obesity?



Excess Body Fat and Disease Risk


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


Long term Regulation of Body Fat: Leptin


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


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)


Tips for Shifting Energy Balance Toward Weight Loss

Class excercise

Break into groups and design a healthy plan for weight loss for me….


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]



Which guideline about weight loss is correct?

Aall 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

Cmost people can reduce health risks with a 5-15% weight loss

Dthe health benefits of weight loss do not begin to accrue until normal weight is achieved


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


Evaluating Weight-Loss Programs: how do you tell healthy diets from fad diets?


Which of these is important when selecting a weight loss program for long-term weight loss

ADoes the program require purchase of special foods?

BDoes the program offer social support?

C

Does the program incorporate and encourage physical activity?

DIs there a book available which explains the diet?


Pros and Cons of Some Commercial Weight-Loss Diets


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


Pros and Cons of Some Commercial Weight-Loss Diets


Common Weight-Loss Supplements


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


Gastric Bypass Surgery


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.

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chapter 7 energy balance and weight management. copyright 2010, john wiley & sons, inc....

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