Energy Balance and Weight Control Dr. David L. Gee FCSN 245-Basic Nutrition.

Energy Balance and Weight Control

Dr. David L. Gee

FCSN 245-Basic Nutrition

Energy Balance

EB = E(in) - E(out) E(in) = dietary intake of energy E(out) = energy expenditure

Energy Balance:The Key to Weight Change

When E(in) < E(out) Negative energy balance weight loss

When E(in) > E(out) Positive energy balance weight gain

When E(in) = E(out) Zero energy balance no weight change

How do you measure:Energy (in)

Calories = energy required to heat 1 kg

water by 1 degree C. Bomb Calorimeter

©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.

How do you measure: E(out) Direct Calorimetry

measures heat directly bomb calorimeter (for food) room calorimeter

Indirect Calorimetry measures oxygen consumed or carbon dioxide produced

The effects of energy imbalance are cumulative!! If: +EB of 100 Cal/day

= +EB of 36,500 Cal/year If 1 lb fat = 3500 Cal Then see wt gain of 10 lbs per year !!!

Therefore, knowing what affects energy balance is important Small consistent daily changes accumulate to large

weight changes

Energy Out Components of E(out):

Basal Metabolic Rate (BMR) Activity (Act) Thermic Effect of Food (TEF)

E(out) = BMR + Act + TEF

Basal Metabolic Rate Energy essential for life support

Circulation Respiration Temperature Maintenance Nerve Transmission Kidney Function, etc

Basal Metabolic Rate Estimation of BMR: BMR = 0.9 - 1 Cal / kg BW / hr Example:

120 lbs / 2.2 lbs/kg = 55 kg BMR = 55 x 1 x 24hr/d BMR = 1320 Cal / day

Basal Metabolic Rate Factors affecting BMR Age

Height

Growth

Body Composition

Basal Metabolic Rate

Factors affecting BMR Fever

Stress

Undernutrition

Energy for Activity Sedentary (adds 25-35% of BMR) Light (35-50%) Moderate (50-70%) Heavy (>70%) Example:

Light Activity = 40% x 1320 = 530 Cal Moderate Activity = 60%x1320= 790 Cal Sedentary = 30%x1320= 396 Cal Mod to Sed = 41 pounds of fat per year!!

Thermic Effect of Food Increased energy expenditure

after a meal. 5-10% of BMR

Cost of digestion, absorption, & assimilation of nutrients

Ex: 5% x 1320 = 60 Cal

Estimation of E(out) E(out) = BMR + Act + TEF

Example: E(out) = 1320 + 530 + 60 = 1910 Cal

BMR = 69% of E(out) Act = 28% of E(out) TEF = 3% of E(out)

Healthy Weight and the Non-Diet Approach

David L. Gee, PhD

Professor of Food Science and Nutrition

Central Washington University

Prevalence of Overweight in the US 1990: 56% of Americans were overweight

23% were obese 2000: 64% of Americans were overweight

30% were obese At this rate

In 2010: 73% overweight In 2020: 84% overweight In 2030: 96% overweight

Increases in overweight/obesity were seen in: Both males and females All age groups All ethnic groups

The increase in prevalence in people with BMI > 25 was almostEntirely due to increased prevalence of obese!!! Overweight may be a transitional state for most Americans !!!

Ethnicity and Overweight (BMI>27.5) Prevalence

White Black Hispanic Native Am Hawaiian

2427 26

45

31

42

3440

6663

0

10

20

30

40

50

60

70

%

White Black Hispanic Native Am Hawaiian

Male

Female

Epidemic Increase in Childhood Overweight, 1986-1998JAMA 286:2845-2848 (2001)

National Longitudinal Survey of Youth 1986-1998 8,270 children, aged 4-12 yrs

Prior studies show it took 30 years for overweight prevalence to double. Current study show doubling time to be less than 12 years. Rate of increase particularly high in African

American and Hispanic children

Prevalence of Overweight Children in the US

Epidemic Increase in Childhood Overweight, 1986-1998JAMA 286:2845-2848 (2001)

Prevalence of overweight in children. CDC (2004)

Overweight = above the 95th percentile for BMI based on NHANES II data from 1970’s

For adolescents 12-19 yrs: 1974 = 7.4% 2002 = 15.6%

Genes/Biology vs Environment Overweight is a result of both Adoption studies (biology)

Adopted adults have BMI that are more similar to biological parents than to adoptive parents.

Animal studies (biology) genetically obese rats and mice

Genes/Biology vs Environment (cont.)

Migration studies (environment) Japanese Hawaiian Japanese Californian Japanese

Dietary Change Studies (biology and environment) SW Native Americans

Pima Indians Mexican Pima Indians

subsistence farming & ranching 20% fat diet, 40 hrs/wk physical work

Arizona Pima Indians mechanized agriculture, sedentary lifestyle 40% fat diet

Pima IndiansArizona Pima Indians are:

1 inch taller 57 pounds heavier 70% obese 50% with diabetes by age 35

Genes vs Environment: Conclusions Genes for weight gain

predisposes some individuals towards weight gain.

Environment determines which of those individuals actually gain weight.

Why lose weight?

Obesity is associated with greater risk of: Diabetes Hypertension & stroke Coronary heart disease Most cancers (except lung cancer) Sleep apnea, arthritis, gall stones, ….

Overfat vs Underfit ???? Good question Vast majority of overfat are underfit

Obesity and Causes of Death in the US

The Obesity Epidemic in America:Who’s responsible?

Personal responsibility Environmental influences

Do we need a “Food Police”? http://www.nytimes.com/2005/06/12/business/yourmon

ey/12food.html?pagewanted=1

What is a “Healthy Weight”?

A broad range of weight which allows for minimal risks for chronic diseases.

Goes beyond using only body weight as a criteria for good health.

Determination of your "healthy weight". Step 1. Body Mass Index

BMI = BW(kg)/Ht2(m2) Dr. Phil

from Nutrition Action Health Letter, Jan. 2004 6‘4" = 78" x 0.0254(m/in)= 1.93m 240lbs / 2.2(lb/kg) = 109kg

BMI = 109/(1.932)=109/3.72 = 29.3

BMI Classifications

BMI = 19 - 25 => Desirable BMI = 25 - 30 => Overweight BMI = 30 - 35 => Obese, category 1 BMI = 35 - 40 => Obese, category 2 BMI > 40 => Severe obesity “Healthy weight is a broad range of weight…”

For 5’10”, BMI 19-25 = 132 – 174 lbs

BMI and Mortality Risk

Healthy Weight (cont.)

If your BMI > 25, then consider presence of other health risk factors.

Healthy Weight (cont.) Body Fat Distribution upper body fatness associated with

higher health risks Waist Circumference (1998 NIH)

> 35” for females, > 40” for males

Healthy Weight (cont.):Know your blood lipids! Hyperlipidemia/dyslipidemia

TC > 240 mg/dl LDL-C > 160 mg/dl HDL-C < 40 mg/dl TG > 200 mg/dl

Healthy Weight (cont.):Know your blood pressure! High Blood Pressure

Systolic BP > 140 mm Hg orDiastolic BP > 90 mm Hg or

Borderline or Pre-hypertensive>130/85

Healthy Weight (cont.):Know your blood sugar and history Hyperglycemia (Diabetes)

Fasting Blood Glucose > 126 mg/dl

Impaired Glucose TolerancePre-diabetic >110 mg/dl

Gestational Diabetes Family History of Diabetes

Healthy Weight Summary

If your BMI is 19-25, you are at a Healthy Weight. Health problems are not weight related

If your BMI is > 25 and you have no other risk factors, you are at a Healthy Weight.

If your BMI is > 25 and you have one or more risk factors, you are NOT at a Healthy Weight. Weight loss is likely to improve your health

Should everybody who is overweight try to lose weight?

Will weight loss improve your quality of life?A Prospective Study of Weight Change and Health-Related

Quality of Life in Women

JAMA Dec. 1999 Nurse’s Health Study

40,098 women, 4 yr longitudinal study Weight changes Quality of life questionnaire

Physical function Vitality Freedom from bodily pain Mental health

The effect of weight gain/loss on:Vitality Score Weight gain:

associated with declines in vitality scores in all BMI categories

Weight loss associated with

improved vitality scores only in women with BMI>25

The effect of weight gain/loss on:Mental Health Score Weight gain

associated with a decline in mental health scores in all weight categories

Weight loss associated with

improved mental health scores only in obese class I women and declined in normal weight women.

A Prospective Study of Weight Change and Health-Related Quality of Life in Women.

Conclusions: For women at all BMI categories:

Don’t gain weight Reduced quality of life

For overweight and obese women: Weight loss is generally associated with improved

quality of life

For normal weight women Weight loss does not improve quality of life

May actually reduce quality of life

Do media images affect your idea of

what you should look like?

2000 Grammy Awards

Do media images actually Contribute to weight problems?

Bottom Line on Weight Loss

Lose weight for the right reasons Improve health and your quality of life

Losing weight to attain the ‘perfect body’ May lead to frustration

And, ironically, weight gain

May lead to eating disorders

Dietary Means to a Healthy Weight

Weight loss occurs when in negative energy balance

Weight loss is only half the battle Maintenance of weight loss is the critical

problem

Dietary Means to a Healthy WeightBalanced Reduced Calorie Diet

Characteristics Calories reduced by 500-1000 Cal/day CHO:PRO:FAT = 50-60%: 10-15%: 20-

30%

Examples Weight Watchers, Jenny Craig, Slim Fast

What the research shows: Short-term outcomes

Modest weight loss, improved health

Long-term outcomes Success rate not great

Dietary Means to a Healthy WeightLow Carbohydrate Diets

Characteristics Very low in CHO Restricted intakes of fruit, cereals, pasta, bread, potatoes, rice Caloric intake not specified

Examples Atkins diet


6 month studies, good weight loss, no substantial change in heart disease risk factor, drop-out rate significant

Long-term outcomes No long term studies, health risks?, 1 yr studies show more weight

regain compared to low-fat diets

Dietary Means to a Healthy WeightThe Carbohydrate ‘Restrained’ Diets

Characteristics Lower in CHO than Dietary Guidelines but

higher than Low Carb diets (~40% CHO, 30%FAT, 30%PRO)

Low glycemic index foods encouraged Monounsaturated fats encouraged

Examples Zone Diet, South Beach Diet

What the research shows: Little research available on these diets

Dietary Means to a Healthy WeightHealthy Diet/Non-Diet Approach

Characteristics Focus on quality of the diet, not quantity Attaining good health is primary goal, not weight loss

Examples DASH diet, Dietary Guidelines, Food Guide Pyramid


Slow, limited weight loss, health benefits Long-term outcomes

U. Colorado’s Weight Loss Registry Diet most adopt in order to maintain weight loss

Exercise and Weight Loss U. Colorado’s Weight Loss Registry

Exercised used by nearly 100% Walking the most common form of exercise

Benefits of Exercise Rate of weight loss greater Caloric restriction not as great Quality of weight loss better Proactive choice vs dieting Health benefits independent of weight loss

Rates of physical inactivity in the US

Exercise and Weight Loss

Structured Exercise Aerobic Exercise

Burns more calories, more fat Stress duration initially

Strength Training Builds more lean tissue Increases basal metabolic rate

Exercise for Weight Loss:Walking vs Running

Going 4 miles

Walking @ 15min/mile

Jogging @ 8 min/mile

Calories burned 400 Cal 400 Cal

Fuels burned:

CHO:FAT

50:50 75:25

Calories CHO 200 Cal 300 Cal

Calories FAT 200 Cal 100 Cal


Going 1 hour

Walking @ 15min/mile

Jogging @ 8 min/mile

Distance covered 4 miles 7.5 miles

Calories burned 400 Calories 750 Calories

Fuels burned:

CHO:FAT

50:50 75:25

Calories CHO 200 Calories 560 Calories

Calories FAT 200 Calories 190 Calories


Conclusions Walking and running burn the same number of

calories over the same distance Walking burns more fat than running over the

same distance Running burns calories at a faster rate and

improves cardiovascular fitness more. Bottom line: Just do it!

Either type of exercise is beneficial


Structured Exercise Characteristics of Successful Programs:

Convenient Enjoyable Safe affordable Subject realizes net benefit over costs


Lifestyle Activity 24 hr day

Sleep/rest = 10 hrs Structured exercise = 1 hr What you do the remaining 13 hrs of the day?

Burn extra 25 Cal/hr = 325 Cal/day = 33 pounds of fat loss per year

Develop a new attitude about being active Pedometers and 10,000 step programs Health benefits significant

Weight Loss/Weight MaintenanceBehavior/Attitude Changes

Pay attention to what you eat Success of weight loss programs

Examine: Triggers for eating

Emotional eating Risky situations

Behavior Modification Programs Track/record eating behaviors Identifies problems Sets goals and establishes rewards Continual reassessment/problem solving

For more severe weight loss:

Prescription Drugs For those with BMI > 30 or For those with BMI >27 and risk factors

Meridia (Sibutramine, Abbott Lab) Suppresses appetite

Increases brain serotonin & norepinephrine levels – signal for satiety

Xenical (Orlistat, Roche) Inhibits fat absorption

Reduces calories from fat containing foods Results in “adverse reactions” if eating high fat foods

Long term success and risks Meridia – hypertension Xenical – steatorrhea (fatty diarrhea)

For those with Severe Obesity Surgical Methods

For those with BMI >40

Carnie WilsonAl Roker

For those with Severe Obesity

Gastroplasty Reduces size of stomach by

banding or stapling Gastric Bypass Surgery

Reduces size of stomach Bypasses much of the small

intestine Outcomes

Rapid and substantial weight loss

Side effects Dangers

Energy Balance and Weight Control Dr. David L. Gee FCSN 245-Basic Nutrition.

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