whitney & rolfes – understanding nutrition, 12 th edition energy balance and body composition...
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Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy Balance and Energy Balance and Body CompositionBody Composition
Chapter 8
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
Direct measure of food’s energy value Bomb calorimeter
Indirect measure of energy released Oxygen consumed
kCalorie calculations
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
Hunger Physiological response to nerve signals and
chemical messengersHypothalamus
Influences Satiation – stop eating Satiety – not to start eating again
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
Overriding hunger and satiety Stress eating
External cues Time of day, availability, sight, taste of food
Environmental influences Examples
Disordered eating
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
Sustaining satiation and satiety Nutrient composition
Protein is most satiatingLow-energy density foods are more satiatingHigh-fiber foods are more satiatingHigh-fat foods – strong satiety signals
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy In: Food Energy In: Food CompositionComposition
The Hypothalamus Control center for eating Integrates messages
Energy intake, expenditure, storage Gastrointestinal hormones
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Energy Out Energy Out
Thermogenesis Basal metabolism Physical activity Food consumption Adaptation
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Components of Energy Components of Energy Expenditure – Basal Expenditure – Basal
MetabolismMetabolism About two-thirds of energy expended in a
day Metabolic activities
All basic processes of life Basal metabolic rate (BMR)
VariationsWeightLean tissue
Resting metabolic rate (RMR)
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Components of Energy Components of Energy Expenditure – Basal Expenditure – Basal
MetabolismMetabolism
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Components of Energy Components of Energy Expenditure – Physical Expenditure – Physical
ActivityActivity Voluntary movement of skeletal muscles Most variable component of energy
expenditure Amount of energy needed
Muscle mass Body weight Activity
Frequency, intensity, and duration
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Components of Energy Components of Energy Expenditure – Thermic Effect Expenditure – Thermic Effect
of Foodof Food 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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Components of Energy Components of Energy Expenditure – Adaptive Expenditure – Adaptive
ThermogenesisThermogenesis Adapt to dramatically changing
circumstances Examples
Extra work done by body Amount expended is extremely variable Not included in energy requirement
calculations
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Estimating Energy Estimating 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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Defining Healthy Body Defining Healthy Body WeightWeight
Ideal Not appearance based
Perceived body image and actual body sizeDamaging behaviors
Subjective Little in common with health
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Defining Healthy Body Defining Healthy Body WeightWeight
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Defining Healthy Body Defining Healthy Body WeightWeight
Body mass index Relative weight for height
BMI = weight (kg)
height (m)2
Health-related classificationsHealthy weight: BMI = 18.5 to 24.9Other classifications
Not a measure of body composition Variations
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Defining Healthy Body Defining Healthy Body WeightWeight
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Defining Healthy Body Defining Healthy Body WeightWeight
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Important information for disease risk How much of weight is fat? Where is fat located?
Ideal amount of body fat depends on person General disease risk levels
Young men: 22%; Men over 40: 25% Young women: 32%; Women over 40: 35%
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Needing less body fat Some athletes
Needing more body fat Example groups
Fat distribution Visceral fat
Central obesity Subcutaneous fat
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Waist circumference Indicator of fat distribution & central obesity
Women: greater than 35 inchesMen: greater than 40 inches
Waist-to-hip ratio Other techniques for body composition
More precise measures
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Body Fat and Its Body Fat and Its DistributionDistribution
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Health Risks Associated Health Risks Associated with Body Weight & Body with Body Weight & Body
FatFat 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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Health Risks Associated Health Risks Associated with Body Weight & Body with Body Weight & Body
FatFat
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Health Risks Associated Health Risks Associated with Body Weight & Body with Body Weight & Body
FatFat Risks associated with being overweight Obesity is a designated disease
Health risks More likely to be disabled in later years Costs
MoneyLives
Yo-yo dieting
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Health Risks Associated Health Risks Associated with Body Weight & Body with Body Weight & Body
FatFat Cardiovascular disease Elevated blood cholesterol & hypertension Central obesity
Diabetes – type II Central obesity Weight gains and body weight
Cancer Relationship is not fully understood
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Health Risks Associated Health Risks Associated with Body Weight & Body with Body Weight & Body
FatFat Inflammation & metabolic syndrome Change in body’s metabolism
Cluster of symptoms Fat accumulation
Inflammation Elevated blood lipids
Promote inflammation
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Highlight 8Highlight 8
Eating Disorders
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Eating DisordersEating Disorders
Three disorders Anorexia nervosa Bulimia nervosa Binge eating disorder
Prevalence of various eating disorders Causes
Multiple factors Athletes and eating disorders
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Female Athlete TriadFemale Athlete Triad
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Other Dangerous Other Dangerous Practices of AthletesPractices of Athletes
Muscle dysmorphia Characteristic behaviors Similarities to others with distorted body
images Food deprivation and dehydration practices
Impair physical performanceReduce muscle strengthDecrease anaerobic powerReduce endurance capacity
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Anorexia NervosaAnorexia Nervosa
Treatment Multidisciplinary approach
Food and weight issuesRelationship issues
After recovery Energy intakes and eating behaviors may
not return to normal High mortality rate among psychiatric
disorders
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Anorexia NervosaAnorexia Nervosa
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Bulimia NervosaBulimia Nervosa
Distinct and more prevalent than anorexia nervosa True incidence is difficult to establish
Secretive natureNot as physically apparent
Common background characteristics of bulimics
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Bulimia NervosaBulimia Nervosa
Binge-purge cycle Lack of control Consume food for emotional comfort
Cannot stopDone in secret
PurgeCathartic Emetic Shame and guilt
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Bulimia NervosaBulimia Nervosa
Negative self-perceptions
Purging Restrictive dieting
Binge eating Stepped Art
Fig. H8-2, p. 266
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Bulimia NervosaBulimia Nervosa
Whitney & Rolfes – Understanding Nutrition, 12th Edition
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
Whitney & Rolfes – Understanding Nutrition, 12th Edition
Eating Disorders in Eating Disorders in SocietySociety
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