Healthful Body Weight

Chapter 11"To lengthen thy life, lessen thy meals."

-Benjamin FranklinUSATODAY.com - Obesity alone puts heart in

jeopardy

Quote of the WeekIf we could give every

individual the right amount ofnourishment and exercise, not too little and not too much, we would have found the safest way to health.-Hippocrates

"Self delusion is pulling in your stomach when you step on the

scales."

Basal Metabolic Rate Energy essential for life support

– circulation– respiration– temperature maintenance– nerve transmission– kidney function, etc

Factors Affecting BMR

Decrease:–aging

–short and stout

–fasting and starvation

–female

Factors Affecting BMR Increase:

– growth– lean body mass & tall– male– Fever, stress– pregnancy/lactation– increase in thyroxin

Thermal Effect of Food

TEF = Thermal 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

Total Energy TE = BMR +TEF + Activities Activities: Any voluntary activities

– Sedentary 25-35% BMR– Light 35-50%– Moderate 50-70%– Heavy >70%– http://www.americaonthemove.org/– USATODAY.com - Study: Obesity rises faster in

poor teens

TE Example If BMR = 1200 Then TEF x 0.1 = 120 If Activity is moderate = 1200 x 0.5 =

600 Then TE = BMR +TEF + Activity TE = 1200 + 120 + 600 = 1920

Energy Balance When E (in) = E (out)

– no weight change When E (in) < E (out)

– weight loss When E (in) > E (out)

– weight gain

Energy (in) Calories = 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.

Measurement of E (out) Direct Calorimetry

– measures heat directly– bomb calorimeter (for food)– room calorimeter

Indirect Caloroimetry– measures oxygen consumed or– carbon dioxide produced

Whole Body Calorimeter

Room Calorimeter

Indirect Calorimetry

Estimation of Energy Out Example: 55kg male BMR = 1 Cal/kg /hr BMR = 55 x 1 x 24 = 1320 Cal/day TEF =.05 x 1320 = 60 Cal Act = .40 x 1320 = 530 Cal TE = BMR + TEF + Act 1910 = 1320 + 60 + 530

Estimating Calorie Estimating Calorie RequirementsRequirements

Mifflin-St.Jeor Men: 10 x wt (kg) + 6.25 x ht (cm) –5 x

age + 5 Women: 10 x wt (kg) + 6.25 x ht (cm) –

5 x age - 161

Mifflin-St. Jeor Woman: 5’6” tall, 130#; 30 years Works as secretary (10 x 59) + (6.25 x 167.7) – (5 x 30) –

(161) = 1327 kcal

Definitions Underweight Overweight Obesity Morbid obesity Study: Super-sizing your food

takes a hidden toll on your pocketbook

Body Weight VS Body Fat

How to determine if weight is optimum?

Ideal Body Weight Determination– Males: 106 # for first 5 ft

Then 6 # per inch above 5 feet eg: 6 ft individual 5ft= 106 # + (12x6) = 178# so 178 + 10% is ideal body weight

– Females: 100 # for first 5 ft Then 5 # per inch above 5 ft

Ways to determine Ideal Body Weight

Weight for Height Tables:– Metropolitan Life Insurance Table– Height & Weight Tables

Body Mass Index– Wt (kg)/ height (MxM)– or (weight (lb)/ height (in x in) )x 705– eg 5’10” person weighing 150 #

BMI = (150/ (70 x70)) x 705 = 21.6 compare to table

BMI Classifications BMI = 18.5-24.9; Normal; Low Risk BMI = 25-29.9; Overweight; Some Risk BMI = 30-35; Class 1 obesity; High Risk BMI = 35-40; Class 2 obesity; Very High

Risk BMI> 40; Class 3 obesity; Extreme Risk Body Mass Index Chart

What do these men have in common?

They are “obese” by BMI standards Is Your Weight Killing You?

Changing Times 'Miss America' Body Type Isn't

American at All Reuters Health

Miss America pageant winners are thinner than ever before, and look nothing like the average US woman, new study findings suggest.

Comparison of Methods (24 yo male, 5’10”,

average frame) 1. 5’ = 106 # + 6# x 10” =166 # 2. Met life. 1999: 151-163, 1959:143-158# 3. BMI. 18.5-24.9 = 127.6-173# 4. US NCHS. 166# 5. NAASO. 166# 6. US Army. 185# Range 127.6-185

Other Methods of Determining Body

Composition Under water weighing (hydrostatic

weighing) Skinfold test Bioelectrical impedance Near Infrared Reactance air displacement (Bod Pod) Dual energy X-ray absorptiometry

(DEXA)

Hydrostatic Weighing

Skinfold Test

Visceral Fat and Subcutaneous Fat

Bio Electrical Impedance

Near Infrared Reactance

Bod Pod

DEXA

Body FatMale Female

Athlete <10% <17%

Lean 10-15% 17-22%

Normal 15-18% 22-25%

Above ave 18-20% 25-29%

Over fat 20-25% 29-35%

Obese 25+% 35+%

Obesity BMI > 30 BW > 20% of standard % body fat: women > 35%, men > 25% Prevalence - 31% obese, 64% overweight Blackwell Synergy: Nutr Bulletin, Vol 31,

Issue 2, pp. 111-114: Obesity and type 2 diabetes (Abstract)

Mystery of ObesityHunger

–physiologicalAppetite

–learnedSatiety

–GI track

Causes for Obesity

Internal Causes– Genetic Inheritance

Leptin: a protein found that suppresses appetite in animals and increases metabolism

– Overweight animals lack Leptin– Overweight people aren’t as responsive to Leptin

as are normal weight people. Leptin is actually higher in overweight people than normal weight people

– Leptin replacement therapy to fight obesity?– ABC News: Can Geneticists Cure Obesity?

Genetically Obese: Lacks

Gene for Leptin

Genetically Obese: Lacks

Gene for Leptin

Receives Leptin No Leptin

Thrifty Gene Theory

Thrifty metabolismConserve energy

–No gene identified

Set Point Theory

Body adjusts to low intake of Calories– Reduce metabolic rate– Conserves Calories

Food Insecurity

Obesity Trends

Enzyme Theory

Lipoprotein Lipase– Picks up triglycerides from lipoproteins in

the blood and stores it in fat cells– High activity of LPL associated with

increased weight

Gene vs Environment: Conclusions

Genes for weight gain predisposes some individuals towards weight gain

Environment determines which of those individuals actually gain weight

The Seattle Times: Food & wine: Super Bowl snack stats to whet your appetite

Weight Gain E (in) > E (out) Which nutrient in excess causes

weight gain? How

– CHO– Protein– Fat– Alcohol

Feasting and Fasting, 1 of 3Feasting and Fasting, 1 of 3

Weight Loss E(in) < E (out) The body’s response to fasting

– glycogen and fat stores– body protein and fat stores

The body’s response to CHO restriction Solution

– decrease energy in– increase energy out– Nutrition Research - adherence to diet determine

s success

Feasting and Fasting, 2 of 3Feasting and Fasting, 2 of 3

Feasting and Fasting, 3 of 3Feasting and Fasting, 3 of 3

Weight loss diets Weight Watchers and Slim-Fast top

diet ratings - Diet and Fitness - MSNBC.com– Wholegrains strongly associated with

keeping

weight off

WIN - Publication - Weight-loss and Nutrition Myths

FTC Warnings Products and programs that promise quick

and easy weight loss are bogus. To lose weight, you have to lower your intake of calories and increase your physical activity.

The faster you lose weight, the more likely you are to gain it back. Experts recommend a goal of about a pound a week.

FTC Warnings There are no miracle weight-loss

products. Be skeptical of products and programs that claim they can keep weight off permanently. Be skeptical about exaggerated claims.

FTC Launches “Big Fat Lie” Initiative Targeting Bogus Weight-loss Claims

Gastroplasty

Gastric Bypass

Gastric Banding