Chapter8

845 views

Published on

Published in: Health & Medicine
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
845
On SlideShare
0
From Embeds
0
Number of Embeds
54
Actions
Shares
0
Downloads
63
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide
  • Figure H8-2 The Vicious Cycle of Restrictive Dieting and Binge Eating
  • Chapter8

    1. 1. Energy BalanceEnergy Balance and Bodyand Body CompositionComposition Chapter 8Chapter 8
    2. 2. Energy BalanceEnergy Balance • Excess energy is stored as fat • Fat is used for energy between meals • Energy balance: energy in = energy out • A shift in balance causes weight changes • Not simply fat changes • 1 pound of fat = 3500 kcalories
    3. 3. Energy In: Food CompositionEnergy In: Food Composition • Direct measure of food’s energy value • Bomb calorimeter • Indirect measure of energy released • Oxygen consumed • kCalorie calculations
    4. 4. Energy In: Food IntakeEnergy In: Food Intake • Hunger • Physiological response to nerve signals and chemical messengers • Hypothalamus • Influences • Satiation – stop eating • Satiety – not to start eating again
    5. 5. Hunger, Satiation, and SatietyHunger, Satiation, and Satiety
    6. 6. Energy In: Food IntakeEnergy In: Food Intake • Overriding hunger and satiety • Stress eating • External cues • Time of day, availability, sight, taste of food • Environmental influences • Examples • Cognitive influences • Disordered eating
    7. 7. Energy In: Food IntakeEnergy In: Food Intake • Sustaining satiation and satiety • Nutrient composition • Protein is most satiating • Low-energy density • High-fiber foods • High-fat foods – strong satiety signals
    8. 8. Energy In: Food IntakeEnergy In: Food Intake • The hypothalamus • Control center for eating • Integrates messages • Energy intake, expenditure, storage • Gastrointestinal hormones
    9. 9. Energy OutEnergy Out • Thermogenesis • Basal metabolism • Physical activity • Food consumption • Adaptation
    10. 10. Energy Out: Basal MetabolismEnergy Out: Basal Metabolism • About two-thirds of energy expended in a day • Metabolic activities • All basic processes of life • Basal metabolic rate (BMR) • Variations • Weight • Lean tissue • Resting metabolic rate (RMR)
    11. 11. Factors that Affect the BMRFactors that Affect the BMR
    12. 12. Energy Out: Physical ActivityEnergy Out: Physical Activity • Voluntary movement of skeletal muscles • Most variable component of energy expenditure • Amount of energy needed • Muscle mass • Body weight • Activity • Frequency, intensity, and duration
    13. 13. Energy Out: Thermic Effect ofEnergy Out: Thermic Effect of FoodFood • Acceleration of GI tract functioning in response to food presence • Releases heat • Approximately 10 percent of energy intake • High-protein foods vs. high-fat foods • Meal consumption time frame
    14. 14. Energy Out: AdaptiveEnergy Out: Adaptive ThermogenesisThermogenesis • Adapt to dramatically changing circumstances • Examples • Extra work done by body • Amount expended is extremely variable • Not included in energy requirement calculations
    15. 15. Components of Energy Expenditure
    16. 16. Estimating EnergyEstimating Energy RequirementsRequirements • Gender • BMR • Growth • Groups with adjusted energy requirements • Age • Changes with age • Physical activity • Levels of intensity for each gender • Body composition & body size • Height • Weight
    17. 17. Defining Healthy Body WeightDefining Healthy Body Weight • Ideal • Not appearance based • Perceived body image and actual body size • Damaging behaviors • Subjective • Little in common with health
    18. 18. Tips for Accepting a Healthy Body Weight
    19. 19. Defining Healthy Body WeightDefining Healthy Body Weight • Body mass index • Relative weight for height • BMI = weight (kg) height (m)2 • Health-related classifications • Healthy weight: BMI = 18.5 to 24.9 • Other classifications • Not a measure of body composition • Variations
    20. 20. BMI and Body ShapesBMI and Body Shapes
    21. 21. Distribution of Body Weights inDistribution of Body Weights in US AdultsUS Adults
    22. 22. Body Fat and Its DistributionBody Fat and Its Distribution • Important information for disease risk • How much of weight is fat? • Where is fat located? • Ideal amount of body fat depends on person
    23. 23. Body Fat and Its DistributionBody Fat and Its Distribution • Needing less body fat • Some athletes • Needing more body fat • Example groups • Fat distribution • Visceral fat • Central obesity • Subcutaneous fat
    24. 24. ““Apple” and “Pear” BodyApple” and “Pear” Body Shapes ComparedShapes Compared
    25. 25. Body Fat and Its DistributionBody Fat and Its Distribution • Waist circumference • Indicator of fat distribution & central obesity • Women: greater than 35 inches • Men: greater than 40 inches • Waist-to-hip ratio • Other techniques for body composition • More precise measures
    26. 26. Common Methods Used toCommon Methods Used to Assess Body FatAssess Body Fat
    27. 27. Health Risks Associated withHealth Risks Associated with Body Weight & Body FatBody Weight & Body Fat • Body weight and fat distribution correlate with disease risk and life expectancy • Correlations are not causes • Risks associated with being underweight • Fighting against wasting diseases • Menstrual irregularities and infertility • Osteoporosis and bone fractures
    28. 28. BMI and MortalityBMI and Mortality
    29. 29. Health Risks Associated withHealth Risks Associated with Body Weight & Body FatBody Weight & Body Fat • Risks associated with being overweight • Obesity is a designated disease • Health risks • More likely to be disabled in later years • Costs • Money • Lives • Yo-yo dieting
    30. 30. Health Risks Associated withHealth Risks Associated with Body Weight & Body FatBody Weight & Body Fat • Cardiovascular disease • Elevated blood cholesterol & hypertension • Central obesity • Diabetes – type II • Central obesity • Weight gains and body weight • Cancer • Relationship is not fully understood
    31. 31. Health Risks Associated withHealth Risks Associated with Body Weight & Body FatBody Weight & Body Fat • Inflammation & metabolic syndrome • Change in body’s metabolism • Cluster of symptoms • Fat accumulation • Inflammation • Elevated blood lipids • Promote inflammation • Fit and fat versus sedentary and slim
    32. 32. Eating DisordersEating Disorders Highlight 8Highlight 8
    33. 33. Eating DisordersEating Disorders • Three disorders • Anorexia nervosa • Bulimia nervosa • Binge eating disorder • Prevalence of various eating disorders • Causes • Multiple factors • Athletes and eating disorders
    34. 34. Female Athlete TriadFemale Athlete Triad • Disordered eating • Unsuitable weight standards • Body composition differences • Risk factors for eating disorders in athletes • Amenorrhea • Characteristics • Osteoporosis • Stress fractures
    35. 35. Female Athlete TriadFemale Athlete Triad
    36. 36. Other Dangerous Practices ofOther Dangerous Practices of AthletesAthletes • Muscle dysmorphia • Characteristic behaviors • Similarities to others with distorted body images • Food deprivation and dehydration practices • Impair physical performance • Reduce muscle strength • Decrease anaerobic power • Reduce endurance capacity
    37. 37. Tips for Combating Eating Disorders
    38. 38. Anorexia NervosaAnorexia Nervosa • Distorted body image • Central to diagnosis • Cannot be self-diagnosed • Malnutrition • Impacts brain function and judgment • Causes lethargy, confusion, and delirium • Denial • Levels are high among anorexics
    39. 39. Anorexia NervosaAnorexia Nervosa • Need for self-control • Protein-energy malnutrition (PEM) • Similar to marasmus • Impact on body • Growth ceases and normal development falters • Changes in heart size and strength • Other bodily consequences
    40. 40. Anorexia NervosaAnorexia Nervosa • Treatment • Multidisciplinary approach • Food and weight issues • Relationship issues • After recovery • Energy intakes and eating behaviors may not return to normal • High mortality rate among psychiatric disorders
    41. 41. Bulimia NervosaBulimia Nervosa • Distinct and more prevalent than anorexia nervosa • True incidence is difficult to establish • Secretive nature • Not as physically apparent • Common background characteristics of bulimics
    42. 42. Bulimia NervosaBulimia Nervosa • Binge-purge cycle • Lack of control • Consume food for emotional comfort • Cannot stop • Done in secret • Purge • Cathartic • Emetic • Shame and guilt
    43. 43. The Vicious Cycle of RestrictiveThe Vicious Cycle of Restrictive Dieting & Binge EatingDieting & Binge Eating
    44. 44. Negative self-perceptions Purging Restrictive dieting Binge eating Stepped Art Figure 8-H2 p257
    45. 45. Bulimia NervosaBulimia Nervosa • Physical consequences of binge-purge cycle • Subclinical malnutrition • Effects • Physical effects • Tooth erosion, red eyes, calloused hands • Clinical depression and substance abuse rates are high
    46. 46. Bulimia NervosaBulimia Nervosa • Treatment • Discontinuing purging and restrictive diet habits • Learn to eat three meals a day • Plus snacks • Treatment team • Length of recovery • Overlap between anorexia nervosa and bulimia nervosa
    47. 47. Diet Strategies for CombatingDiet Strategies for Combating Bulimia NervosaBulimia Nervosa
    48. 48. Binge-Eating DisorderBinge-Eating Disorder • Periodic binging • Typically no purging • Contrast with bulimia nervosa • Compare with bulimia nervosa • Feelings • Differences between obese binge eaters and obese people who do not binge • Behavioral disorder responsive to treatment
    49. 49. Eating Disorders in SocietyEating Disorders in Society • Society plays central role in eating disorders • Known only in developed nations • More prevalent as wealth increases • Food becomes plentiful • Body dissatisfaction • Characteristics of disordered eating

    ×