Weight loss and exercise

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Weight loss and exercise
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Obesity

• Overweight BMI 25.0 - 29.99
• Obesity
• BMI 30
• Body fat gt 25 for men
• Body fat gt 30 for women
• Americans
• Overweight 32
• Obese 34

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Obesity

• Genetic factors
• 25 of the transmissible variance for fat mass
  and percent body fat
• Cultural factors (30)
• Individual choices (45)

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Calorie

• A measure of HEAT
• (1 calorie heat required to raise 1 gram of
  water by 1 degree Celcius in temperature)
• Heat, or Calorie, represents Energy

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Weight Loss

• Caloric balance or imbalance
• Energy In gt Energy Out Weight Gain
• Energy In lt Energy Out Weight Loss
• Examples
• Energy In Big Mac 540 kcal
• Energy Out Run 40 minutes

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Energy Out

• Caloric expenditure
• Resting Metabolic Rate 60-75
• Thermic effect of food 10
• Physical activity 15-30 of daily caloric
  expenditure
• Example 3000 calories in one day
• RMR 1,800-2250 kcal
• TEF 300 kcal
• PA 450-900 kcal

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Energy In

• Fat 9 calories per gram
• Alcohol 7 calories per gram
• Carbohydrate 4 calories per gram
• Protein 4 calories per gram

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Weight Loss

• Reduce Energy In and/or Increase Energy
  Out...
• 500-1000 fewer calories per day
• (3,500-7,000 fewer calories per week)
• Recommendations
• 1-2 lbs of weight loss per week

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Reducing Caloric Intake
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Reducing Calorie Intake
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Rapid Weight Loss / Low Calorie Diets

• weight loss greater than 1-2 pounds per week.
• Where does the weight loss come from?
• Water loss, Muscle loss, etc.
• Metabolic rate?

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Caloric Intake and Resting Metabolic Rate
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Metabolic Rate

• Resting Metabolic Rate is VO2 measured at rest
• ave. resting VO2 3.5 ml/kg/min
• Estimated RMR 1 kcal/kg/hour
• For a 183 pound person, RMR 2000 kcals.
• 60-75 of daily caloric expenditure

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Metabolic Rate

• Genetics
• Gender
• Fat-free mass
• Dieting
• Hormones (e.g. Thyroid hormones, etc)
• Over eating (thermogenesis)
• Medications/Drugs

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Increasing Caloric Expenditure
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Physical Activity and Body Fat
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Exercise and Weight Loss

• Exercise alone
• less effective than diet alone
• Duration
• gt 2000 calories/wk
• EXAMPLES OF KCAL expenditure
• 0.77 kcal / kg / mile for walking
• 1.53 kcal / kg/ mile for running

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Exercise and Weight Loss

• Exercise may be most critical to help maintain
  weight loss
• Exercise helps to maintain muscle mass and
  metabolic rate

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Exercise and Weight Loss

• Aerobic exercise v Resistance exercise
• WORKOUT CALORIES
• resting metabolic rate
• Aerobic Exercise Duration versus Intensity

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Fat Burning Zone?
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Exercise and Fat Metabolism

• Is low-intensity exercise best for burning fat?
  A Closer Look 4.3

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Successful Weight Loss

• diet and exercise
• Diet limited caloric intake (source of calories
  is unimportant)
• Exercise increase physical activity

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Weight Gain

• Genetics
• Body Type / Somatotype

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Weight Gain

• Caloric intake greater than caloric expenditure.
• 25-30 calories per pound of body weight to gain
  weight (20 calories per pound to maintain weight)
• ...or...
• 500-1000 extra calories per day.

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Weight Gain

• Caloric distribution
• Carbohydrates - 60 to 70 of total calories
• Protein - 10 to 15 of total calories
• Fat - remainder of total calories.

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Weight Gain

• Example for 200 pounds.
• Carbohydrates energy for anabolism (3000 kcals)
• Protein amino acids for anabolism (1200 kcals)
• Fat cant avoid it (800 kcals)
• PSM

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Weight Gain

• Recovery/Rest
• Eccentric muscle contractions damage muscle
  proteins.
• Proteins are replaced for the next 48 hours or
  more.
• Adequate rest and recovery period are critical
  for complete muscle repair and growth