Body Fat Critical part of the human body Essential fat: minimal amount needed by the body Used in temperature regulation, shock absorption, organ protection, nutrient regulation Non-essential fat: stored as adipose tissue
Body Fat Essential –Males: 3% –Females: 10-12% Norms for college aged individuals –Males: 15-20% –Females: 20-25% >25% & >30% = excessive weight that can affect health
Obesity The result of excess fat storage Imbalance of energy intake and expenditure Performance vs. good health Excessive fat may impair physical activity
Android Obesity “Apples” Regional fat storage in abdomen and upper body Related to stroke, CV disease, and diabetes
Gynoid Obesity “Pears” Fat storage below waist Related to genetics
Energy Energy intake: type and quantity of food consumed Energy expenditure: body metabolism Metabolism: rate at which our bodies burn energy (calories) Basal metabolism: number of calories expended at rest
Energy Cont. Exercising metabolism: any energy expenditure over basal metabolism Basal metabolism vs. Exercising metabolism –Determines whether weight is gained, lost, or maintained
Creeping Obesity Small positive caloric balance over time Results in body weight gain Lifestyle behaviors, decrease physical activity, decrease basal metabolism
Caloric Information Definition of calorie: The energy value of food vs. the cost of activity 3500 calories = 1 pound In a months time, if you consume 3500 more calories than you burn, you will gain one pound 1500 calories minimum for males 1200 minimum for females
Causes of Obesity Labor saving devices Technology Genetics Family lifestyle Childhood fatness
Hydrostatic Weighing Most accurate Margin of error 2.5% Time consuming, expensive, complex procedure
Skinfold Measurement Measured by use of skinfold calipers Margin of error 3.7% Sites for males and females vary Number of sites varies: 2,3,5,or 7 site test
Skinfold Measurement #2 Fairly accurate Time saving Less costly Most commonly used technique
Bio-Electrical Impedance Measures the resistance to the flow of electrical current in the body –Electricity will flow through the tissue offering least resistance (lean tissue) Expensive Not very valid
Girth Measurements Used by the military Inaccurate for some
Requirements To Lose Or Maintain Weight Low fat diet Limit refined carbohydrates Diet high in complex carbohydrates and fiber A lifetime of exercise
Weight Loss In order to burn stored fat, aerobic activity needs to last 45 minutes or longer
Key to Attaining Goals: Alter your lifestyle in ways you can “live with” Take one step at a time
Suggestions Helpful In Meeting Goals Record food intake Analyze eating patterns Alter the eating environment Avoid total deprivation of favorite foods Make good food choices Reduce calories and exercise
Weight Management #2 Example: –Reduce caloric intake by 200-300 calories per day –Increase caloric expenditure by 200 - 300 calories per day (approx. 100 calories burned per mile) –600 calorie deficit over 7 days = 4200 calories or >1 lb. lost
Weight Management #3 Example: walk/run 3 times a week (3 miles) = 900 calories burned –In 1 month, one pound is lost –In one year, 13.5 pounds are lost Weight loss as a result of exercise = 80- 90% fat tissue (10-20% lean tissue)
Weight Management #4 Weight loss as a result of diet alone = 35-45% of the weight lost will be lean tissue Aerobic activity and resistive training should be included in any weight control program.
Hierarchy of Nutrient Utilization Carbohydrates –Are not easily stored as fat Fats –Increases caloric intake –Easily stored as fat Proteins – Are burned as a last resort (for the most part) and are not easily stored as fat Two best fuels for activity: –Carbohydrates and fats
Set Point Theory Is there a body fat thermostat or body “fatometer”? Theory: Every individual has a particular body fat level that their body tries to maintain.
Lowering Your Set Point Exercise (aerobic) Low fat, high carbohydrate diet Diets high in fat, refined sugars, and artificial sweeteners have been shown to raise set point levels.
Eating Disorders 59-61% of Americans are overweight 14% are underweight Anorexia nervosa Bulimia Most are in denial
Anorexia Nervosa: General Characteristics Self-imposed starvation Primarily females Psycho-social eating disorder Intense, inappropriate, unmanaged fear of fatness, despite being underweight Distorted body perception Often begins around puberty (perfectionist / dominating mother)
Bulimia: Descriptive Characteristics Are of normal or slightly below normal weights Binge, purge cycles Self-induced vomiting / laxatives Excessive exercise Intense, extreme, negative perception of self
Bulimia: Statistical Data Higher rate of affliction in females 20% of female college population demonstrate bulimic behaviors at some time.