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