Chapter 5 -- Principles of Weight Control

1. Introduction

• Overweight- An excessive amount of weight against a given standard
• Obesity- A chronic disease characterized by an excessively high amount of fat in relation to lean body mass
• There are also problems with being underweight -- Pressure to become and stay thin can lead to eating disorders
• Extreme weight loss can lead to serious medical conditions (heart damage, shrinkage of internal organs, etc.)

2. Obesity and Overweight

• According to 1993 estimates, 65% of adults in the U.S. were over their recommended bodyweight
• Obesity is a major risk factor for diseases of the cardiovascular system
• Obesity has also been associated with Cancer, diabetes, and other health problems
• About 50% of women and 25% men are on diets at any given time
• Most overweight people are not obese
• People should be realistic about weight loss programs

3. The Weight-loss Dilemma

• Yo-Yo dieting carries as great a risk to ones health as remaining overweight
• The body is highly resistant to weight changes through caloric restrictions alone
• Fad diets appeal to many people -- A diet must be something you can LIVE WITH!
• Most fad diets work through loss of water and protein, not fat
• The BEST method for weight loss is a moderate reduction in caloric intake with a moderate increase in caloric expenditure! [if I increase my exercise by 1% and decrease…]

4. Eating disorders

• Anorexia Nervosa

• A condition of self-imposed starvation to lose and maintain very low body weight (most are women)
• Anorexics also have a distorted body image and sometimes combine extreme dieting with extreme physical behaviors!
• Many problems can be reversed -- Treatment usually requires professional help

• Bulimia

• A pattern of binge eating and purging
• The binge-purge cycle usually occurs in stages:

~ Stressful event

~ Binge eating

~ Guilt/Fear

~ Purging

• The most common form of purging is self-induced vomiting
• Strenuous bouts of exercise are common in bulimics
• Can be treated successfully when the person realizes the behavior is destructive and not the "Answer"

5. Physiology of Weight Loss

• The energy balancing equation

• When caloric input equals caloric output à There is no weight change
• If input is greater à There is weight gain
• If output is greater à There is weight loss
• One pound of fat represents about 3500 calories

• Setpoint Theory

• We have a set point for fat storage
• The body works like a thermostat to control body weight
• If consumption decreases, the body adjusts to conserve energy
• If consumption increases, the body adjusts to expend energy
• Dieting can cause you to gain weight [how?]
• A person should not go below 1200(women) and 1500(men) calories/day
• Weight loss should be gradual
• The set point can be lowered by:

1. Aerobic exercise
2. A diet high in complex carbohydrates
3. Nicotine
4. Amphetamines

• The set point can be raised by:

1. A diet high in refined carbohydrates
2. Near-fasting diets
3. Artificial sweeteners (possibly)

• Recommendations:

1. Eat small amounts of food
2. Increase complex carbohydrates and fiber
3. Decrease sugars and fats

• Fat substitutes add no calories but may encourage poor eating habits
• A diet should be a permanent change -- NOT a temporary tool

6. Diet and Metabolism

• Weight loss by diet alone decreases lean body mass
• Weight loss by "diet & exercise" decreases fat
• Loss of lean body mass can:
  • Weaken muscles
  • Damage organs
  • Slow metabolism
  • Cause disturbances in heart function

• Metabolic rate slows because people slow down (not because of age)
• Basal metabolism is directly related to body composition
• Metabolism is the process of using oxygen to burn calories
• The more lean tissue, the higher the metabolic rate
• Exercise is vital to weigh loss and maintenance
• A combination of aerobic and strength-training works best
• Health weight gain
  • "skinny" people should exercise and increase calorie intake
  • Weight gain through diet alone increases fat
  • Strength-training works BEST

• Weight-loss myths:
  • Spot reducing (global)
  • Loosing cellulite (Specific exercises will NOT get rid of specific fat)
  • Sweat suits (Water loss-dehydration)
  • Steam baths/Saunas (Water loss - Replace or death occurs)
  • Mechanical vibrators (fat cannot be rolled or shaken off)

• Medical exam should be taken before starting a weight-loss program
• Don't do too much too fast!

• Strategies for weight loss:
  • Make a commitment to change
  • Set realistic goals
  • Exercise and eat healthy
  • Avoid automatic eating
  • Stay busy and plan meals
  • Cook wisely
  • Don't serve more food than necessary
  • Eat slowly
  • Avoid social binges/eating out
  • No raids on the "frig"/cookie jar
  • Manage stress
  • Reward accomplishments and think positive

• Conclusion: Weight loss is accomplished with a LIFETIME commitment to physical activity and a proper diet!

< Back | Next >