chapter 9 energy balance and healthy body weight

Chapter 9Chapter 9

Energy Balance and Healthy Energy Balance and Healthy Body WeightBody Weight

Nutrition: Concepts & Controversies, 12e Nutrition: Concepts & Controversies, 12e Sizer/WhitneySizer/Whitney

Learning ObjectivesLearning Objectives

Delineate the health risks of too little and too much body fatness, with emphasis on central obesity and its associated health risks.

Describe the roles of BMR and several other factors in determining an individual’s daily energy needs.

Learning ObjectivesLearning Objectives

Calculate the BMI when given height and weight information for various people, and describe the health implications of any given BMI value.

Compare and contrast the roles of the hormones ghrelin and leptin in appetite regulation, and name several other influences on both hunger and satiety.

Learning ObjectivesLearning Objectives

Discuss the potential impact of “outside the body” factors on weight-control efforts.

Develop a weight-loss plan that includes controlled portions of nutrient-dense foods to produce gradual weight loss while meeting nutrient needs.

Discuss the role of physical activity in maintaining a healthy body composition.

Learning ObjectivesLearning Objectives

Defend the importance of behavior modification in weight loss and weight maintenance over the long term.

Compare and contrast the characteristics of anorexia nervosa and bulimia nervosa, and provide strategies for combating eating disorders.

IntroductionIntroduction

Health risks Overweight Underweight

Weight “control” Focus on weight Focus on controlling weight Focus on short-term endeavors

Body composition

The Problems of Too Little or Too The Problems of Too Little or Too Much Body FatMuch Body Fat

U.S. prevalence Underweight Overweight

Epidemic

Children and adolescents

Increasing Prevalence of ObesityIncreasing Prevalence of Obesity

Adult Obesity and Overweight Adult Obesity and Overweight Compared with Compared with Healthy PeopleHealthy People Target Target

Underweight, Overweight, and Underweight, Overweight, and Mortality Mortality

What Are the Risks from What Are the Risks from Underweight?Underweight?

Disadvantages Siege or famine Hospital stays Wasting disease Heart disease

What Are the Risks from Too What Are the Risks from Too Much Body Fat?Much Body Fat?

Obesity-related illnesses Dying young

Obesity vs. smoking Hypertension Central obesity Other risks

What Are the Risks from Central What Are the Risks from Central Obesity?Obesity?

Risks of visceral fat Subcutaneous fat

Adipokines Regulate inflammatory processes Central obesity causes a shift

Free fatty acids Factors affecting fat distribution

Visceral Fat and Subcutaneous Visceral Fat and Subcutaneous FatFat

How Fat Is Too Fat?How Fat Is Too Fat?

Evaluate health risks of obesity Body mass index (BMI) Waist circumference Disease risk profile

Social costs of being overfat Economic costs of being overfat

Chronic Disease Risks According to Chronic Disease Risks According to BMI Values and Waist CircumferenceBMI Values and Waist Circumference

Indicators of an Urgent Need for Indicators of an Urgent Need for Weight LossWeight Loss

The Body’s Energy BalanceThe Body’s Energy Balance

Energy budget Change in energy stores = energy in –

energy out Energy in

Foods and beverages Energy out

Varies widely Lifestyle and metabolism

The Body’s Energy BalanceThe Body’s Energy Balance

Calorie needs Monitor activity and weight Energy output

Basal metabolism (BMR)Voluntary activitiesThermic effect of food

Components of Energy Components of Energy ExpenditureExpenditure

Factors That Affect the BMRFactors That Affect the BMR

The Body’s Energy BalanceThe Body’s Energy Balance

Estimated energy requirements (EER) Reference man and woman Taller people

Need more energy Energy need diminishes with age

DRI method Gender, age, physical activity, body size

and weight, and growth

Body Weight Versus Body Body Weight Versus Body FatnessFatness

Body Mass Index (BMI) Underweight Overweight Obesity Risks follow racial lines Drawbacks

Amount or location of fat Diagnosis requirements

Measuring Waist CircumferenceMeasuring Waist Circumference

Measures of Body Composition Measures of Body Composition and Fat Distributionand Fat Distribution

Body composition Skin fold test Underwater weighing Bioelectrical impedance Dual-energy X-ray absorptiometry Each method has advantages and

disadvantages

Average Body Composition of Average Body Composition of Men and WomenMen and Women

Three Methods of Assessing Body Three Methods of Assessing Body FatnessFatness

How Much Body Fat Is Ideal?How Much Body Fat Is Ideal?

Healthy BMI range Man: 12 to 20 percent Woman: 20 to 30 percent

Declaration of being overfat Men age 40 and younger Men over age 40 Women age 40 and younger Women over age 40

The Mystery of ObesityThe Mystery of Obesity

Obesity’s cause remains elusive Hunger

Satiety Response to physiological need

Chemical messengers Stomach hormone

Ghrelin Stomach capacity

Hunger, Appetite, Satiation, and Hunger, Appetite, Satiation, and SatietySatiety

The Mystery of ObesityThe Mystery of Obesity

Appetite Initiates eating Endorphins Factors affecting

appetite

The Mystery of ObesityThe Mystery of Obesity

“Stop” signals Satiation

Food in digestive tractHormonesHypothalamus

Satiety Regulates frequency of meals

The Mystery of ObesityThe Mystery of Obesity

Leptin Adipokine hormone Appetite regulation Leptin resistance

Energy nutrients Protein provides most satiation

Inside-the-Body Causes of Inside-the-Body Causes of ObesityObesity

Metabolic theories Variations in ease of body fat gain or loss Variety of theories

Genetics Influence tendency to gain weight or stay

lean Environmental factors

Outside-the-Body Causes of Outside-the-Body Causes of ObesityObesity

External cues to overeating Available foods Human sensations Larger portions

Physical inactivity Nonexercise activity thermogenesis (NEAT) Inactivity epidemic Sitting still and death from heart disease

Outside-the-Body Causes of Outside-the-Body Causes of ObesityObesity

Built environment Can discourage physical activity

Food access Food deserts Fast food

Attain healthy body weight Diet Physical activity Behavior change

How the Body Loses and Gains How the Body Loses and Gains WeightWeight

Tissue lost or gain Depends on what you do

WaterFat or muscle

Smoking Hazards

Moderate Weight Loss Versus Moderate Weight Loss Versus Rapid Weight LossRapid Weight Loss

Gradual weight loss is preferred Fasting

Body adjustmentsSacrifice lean tissue

Death Ketosis

Break down of fat molecules

Feasting and FastingFeasting and Fasting

Moderate Weight Loss Versus Moderate Weight Loss Versus Rapid Weight LossRapid Weight Loss

Short-term fasting Seems to be tolerated Effects of deprivation

Overeat or binge eating Weight loss technique

Slowing of metabolism

Low-carbohydrate diets DRI minimum carbohydrate intake level

Weight GainWeight Gain

Energy-yielding nutrients contribute to body stores Four sources of energy

Alcohol Two types of energy stores

An excess of any food will become fat

Popular Fad DietsPopular Fad Diets

Effectiveness Both sides of the coin

Adequacy To be achieved via food, not supplements

Safety Personal responsibility

Achieving and Maintaining a Achieving and Maintaining a Healthy Body WeightHealthy Body Weight

Changing your body weight What is your

motivation? Benefits of modest

weight loss Focus on health or

fitness

Tips for Accepting a Healthy Body Tips for Accepting a Healthy Body WeightWeight

What Diet Strategies Are Best for What Diet Strategies Are Best for Weight Loss?Weight Loss?

Aim for a realistic target Reasonable goals Specific and measurable objectives

Recommended weight loss 1 to 2 pounds per week Weight maintenance

Keep records Plan your diet

What Diet Strategies Are Best for What Diet Strategies Are Best for Weight Loss?Weight Loss?

Realistic calorie intakes Nutrient needs and caloric intake

MenWomen

Adequate diets Choose sensibly

Consider a supplement Calcium

Recommended Daily Food Recommended Daily Food Intakes for Low-Calorie DietsIntakes for Low-Calorie Diets

What Diet Strategies Are Best for What Diet Strategies Are Best for Weight Loss?Weight Loss?

Manage portion sizes Reduced-calorie foods Read labels

Calorie calculations Little daily decisions add up

Energy density Low energy density

May not reflect nutrient density

Examples of Energy DensityExamples of Energy Density

What Diet Strategies Are Best for What Diet Strategies Are Best for Weight Loss?Weight Loss?

Artificial sweeteners Soft drinks and milk consumption

Meal spacing Hunger vs. appetite Importance of breakfast Night eating syndrome

Physical Activity in Weight Loss Physical Activity in Weight Loss and Maintenanceand Maintenance

Weight loss Physical activity alone

Weight maintenance Appetite effects

Suppression of appetite Heightened satiety

Other benefits Choosing activities

What Strategies Are Best for What Strategies Are Best for Weight Gain?Weight Gain?

Physical activity Resistance training

High-calorie diet Increased daily caloric intake High energy density foods

Portion sizes and meal spacing Avoid tobacco

Medical Treatment of ObesityMedical Treatment of Obesity

Obesity medications Over-the-counter (OTC) medications Prescription medications

Obesity surgery Extreme obesity Not a sure cure Complications

Lipectomy

Surgical Obesity TreatmentsSurgical Obesity Treatments

Herbal Products and GimmicksHerbal Products and Gimmicks

Herbals and botanicals Sold as ‘dietary supplements’

Lack of FDA approval

Other gimmicks Prohibited claims Saunas or steam baths Cellulite

Once I’ve Changed by Weight, Once I’ve Changed by Weight, How Can I Stay Changed?How Can I Stay Changed?

Lifelong commitment Cultivate habits for

a healthy weight Self-efficacy and

success keys Physical activity

Weight cycling

Behavior Modification for Weight Behavior Modification for Weight ControlControl

Behavior modification Change behavior Change thought processes

Food and activity diary Don’t attempt to modify all behaviors at once

A Sample Food and Activity DiaryA Sample Food and Activity Diary

Behavior Modification for Weight Behavior Modification for Weight ControlControl

Modifying behaviors Eliminate inappropriate cues Suppress cues Strengthen cues Repeat the desires behaviors Emphasize negative consequences Emphasize positive consequences

Establish baseline Cognitive skills

The Perils of Eating DisordersThe Perils of Eating Disorders

Controversy 9

IntroductionIntroduction

Eating disorders Anorexia nervosa Bulimia nervosa Binge eating

disorder Young women

All people Beginnings of

disorders

Society’s InfluenceSociety’s Influence

Many causes to eating disorders Societal pressure for thinness

Distorted body image

Media messages Unrealistic ideals

Dieting as risk

Eating Disorders in AthletesEating Disorders in Athletes

Motivations Risk factors

Male and female athletes Female athlete triad

Three medical problems Male athletes and eating disorders

Muscle dysmorphia

The Female Athlete TriadThe Female Athlete Triad

Tips for Combating Eating Tips for Combating Eating DisordersDisorders

Anorexia NervosaAnorexia Nervosa

Characteristics Cannot recognize condition

Role of the family Self-starvation Physical perils

Damage to whole body Death

Treatment

Criteria for Diagnosis of Anorexia Criteria for Diagnosis of Anorexia NervosaNervosa

Bulimia NervosaBulimia Nervosa

Characteristics More prevalent than anorexia nervosa

Role of the family Binge eating and purging

Stages of a binge Methods for purging

Physical and psychological perils Treatment

Criteria for Diagnosis of Bulimia Criteria for Diagnosis of Bulimia NervosaNervosa

The Cycle of Bingeing, Purging, The Cycle of Bingeing, Purging, and Negative Self-Perceptionand Negative Self-Perception

Binge Eating DisorderBinge Eating Disorder

Differences from bulimia nervosa

Responds more readily to treatment

Criteria for Diagnosis of Binge Criteria for Diagnosis of Binge Eating DisorderEating Disorder