Case Study
Weight Management and Energy Balance
© 2015 Pearson Education, Inc.
Chapter 10
Lecture Outline
1
Objectives for Chapter 10
Explain the concept of a healthy weight and differentiate between the conditions of underweight, overweight, and obesity.
Define how you know you are at a healthy weight.
Explain what energy balance is, what determines your daily energy needs, and the effects of an energy imbalance.
Explain the factors that affect your body weight.
Explain how to lose weight healthfully.
Describe a basic plan for healthy weight maintenance.
Describe how to gain weight healthfully.
Define disordered eating and discuss the warning signs of and treatment options for eating disorders.
© 2015 Pearson Education, Inc.
2
What Is a Healthy Weight and Why Is Maintaining It Important?
Healthy weight: body weight relative to height that doesn't increase the risk of developing weight-related health problems or diseases
Weight management: maintaining weight within a healthy range
Overweight: 10 to 15 pounds more than healthy weight
69 percent of Americans are overweight
Obesity: 25 to 40 pounds more than healthy weight
36 percent of Americans are obese
© 2015 Pearson Education, Inc.
3
What Is a Healthy Weight and Why Is Maintaining It Important?
Being overweight increases risk of:
Hypertension and stroke
Heart disease
Gallbladder disease
Type 2 diabetes
Osteoarthritis
Some cancers
Sleep apnea
Losing 5 to 10 percent of body weight can produce health benefits
© 2015 Pearson Education, Inc.
4
What Is a Healthy Weight and Why Is Maintaining It Important?
Underweight: weighing too little for your height
May be caused by excessive calorie restriction and/or physical activity, underlying medical condition, emotional stress
Risks for:
Young adults: nutrient deficiencies, electrolyte imbalance, low energy levels, decreased concentration
Older adults: low body protein and fat stores, depressed immune system, medical complications
© 2015 Pearson Education, Inc.
5
Increase in Obesity Rates in the United States
© 2015 Pearson Education, Inc.
6
How Do You Know If You're at a Healthy Weight?
BMI measurements can provide a general guideline:
Body mass index (BMI) = weight (lb) x 703 height squared (in2)
BMI ≥ 25 is overweight: modest increase in risk of dying from diseases
≥ 30 is obese: 50 to 100 percent higher risk of dying prematurely compared to healthy weight
< 18.5 is underweight; can also be unhealthy
© 2015 Pearson Education, Inc.
7
What's Your BMI?
© 2015 Pearson Education, Inc.
Figure 10.1
8
How Do You Know if You're at a Healthy Weight?
Measure your body fat and its location
Average healthy adult male between 20 and 49 years of age: 16 to 21 percent of weight is body fat
Average healthy female: 22 to 26 percent body fat
Techniques to measure body fat include skinfold thickness measurements and bioelectrical impedance
Central obesity (excess visceral fat) increases risk of heart disease, diabetes, hypertension
Measure waist circumference
© 2015 Pearson Education, Inc.
9
© 2015 Pearson Education, Inc.
Table 10.1
10
Visceral and Subcutaneous Fat Storage in the Body
© 2015 Pearson Education, Inc.
Figure 10.2
11
How to Measure Waist Circumference
© 2015 Pearson Education, Inc.
Figure 10.3
12
How at Risk Are You?
© 2015 Pearson Education, Inc.
Figure 10.4
13
Discussion Questions
How can a person who is "normal" weight be at risk for obesity-related diseases?
What are health risks of women who are normal weight obese?
In addition to increased percentage of body fat, what characteristic of body fat points to increased health risks?
© 2015 Pearson Education, Inc.
Can You Be Slim and Obese? Hidden Risk of Normal Weight Obesity
What Is Energy Balance and What Determines Energy Needs?
Energy balance is calories in versus calories out
Positive energy balance: more calories consumed than expended (leads to fat storage, weight gain)
Negative energy balance: more calories expended than consumed (leads to weight loss)
Energy needs are different for everyone
Energy needs comprise:
Basal metabolism
Thermic effect of food
Physical activities
© 2015 Pearson Education, Inc.
15
Energy Balance and Imbalances
© 2015 Pearson Education, Inc.
Figure 10.5
16
The Three Components of Your Energy Needs
© 2015 Pearson Education, Inc.
Figure 10.6
17
What Is Energy Balance and What Determines Energy Needs?
Your BMR is the minimum amount of energy you need to function
Amount needed to meet basic physiological needs, keep you alive
Makes up about 60 percent of total energy needs
Many factors affect BMR, chiefly lean body mass
The thermic effect of food affects your energy needs
Amount of calories expended to digest, absorb, and process food (about 10 percent of calories in food eaten)
© 2015 Pearson Education, Inc.
18
© 2015 Pearson Education, Inc.
Table 10.2
19
What Is Energy Balance and What Determines Energy Needs?
Physical activity will increase your energy needs
Energy expended by sedentary people = less than half of BMR
Very active athletes can expend twice BMR
Exercise causes small increase in energy expenditure after activity has stopped
Calculating your energy needs:
Estimated energy requirement (EER): daily energy need based on age, gender, height, weight, activity level
© 2015 Pearson Education, Inc.
20
© 2015 Pearson Education, Inc.
Misc 10.28
21
Energy Imbalances over Time Can Lead to Changes in Body Weight
Reducing calories can lead to weight loss
Stored glycogen and fat are used as fuel sources
Amino acids from body protein breakdown can be used to make glucose
Prolonged fast depletes all liver glycogen
Ketone bodies generated from incomplete breakdown of fat
Fat stores and about one-third of lean tissue mass depleted in about 60 days
© 2015 Pearson Education, Inc.
22
What Are the Effects of an Energy Imbalance?
Excess calories can lead to weight gain
Excess calories are stored as fat, regardless of source
Limited capacity to store glucose as glycogen
Can't store extra protein
Unlimited capacity to store fat
Body contains about 35 billion fat cells, which can expand
© 2015 Pearson Education, Inc.
23
What Factors Are Likely to Affect Body Weight?
Factors in weight management: what and how often you eat, physiology, genetics, environment
Hunger and appetite affect what you eat
Appetite is psychological desire for food
Hunger is physiological need for food; subsides as feeling of satiation sets in
Satiety determines length of time between eating episodes
© 2015 Pearson Education, Inc.
24
What Factors Are Likely to Affect Body Weight?
Physiological mechanisms help regulate hunger
Many hormones play a role:
Ghrelin: produced in stomach when empty; increases hunger
When fat stores increase, leptin in fat tissue signals brain to decrease hunger and food intake.
Cholecystokinin: released when stomach is distended, increasing feelings of satiation, decreasing hunger
Protein, fatty acids, and monosaccharides in small intestine stimulate feedback to brain to decrease hunger
Insulin also causes brain to decrease hunger
Many people override feedback mechanisms, resulting in energy imbalance
© 2015 Pearson Education, Inc.
25
What Factors Are Likely to Affect Body Weight?
Genetics partially determines body weight
Risk of becoming obese doubles if parents are overweight, triples if obese, five times greater if severely obese
Confirmed by studies of identical twins separated at birth
© 2015 Pearson Education, Inc.
26
What Factors Are Likely to Affect Body Weight?
Genetic differences in level or function of hormones, such as high ghrelin or low leptin levels, increase obesity
Many obese have adequate leptin, but brain has developed resistance to it
Genetic differences in non-exercise-associated thermogenesis (NEAT): energy expenditure in nonexercise movements, such as fidgeting, standing, chewing gum
"Set point" theory holds that body opposes weight loss and works to maintain a set weight
© 2015 Pearson Education, Inc.
27
What Factors Are Likely to Affect Body Weight?
Environmental factors can increase appetite and decrease physical activity
Environment of cheap and easily obtainable energy-dense foods stimulates appetite
Gene-environment interaction: increases risk of obesity in some people
We work more and cook less
32 percent of calories come from ready-to-eat foods prepared outside of home
Frequent dining out associated with higher BMI
© 2015 Pearson Education, Inc.
28
What Factors Are Likely to Affect Body Weight?
We eat more (and more)
Increased availability of food-service establishments and access to large variety of foods, larger portions encourage people to eat more
We sit more and move less
Americans are eating about 600 calories/day more than in 1970
Labor-saving devices at work and home, sedentary leisure activities ("screen time") result in decreased energy expenditure
© 2015 Pearson Education, Inc.
29
Environmental and Lifestyle Factors of Weight Gain
© 2015 Pearson Education, Inc.
Figure 10.7
How Can You Lose Weight Healthfully?
National Institutes of Health: overweight individuals should aim to lose about 10 percent of body weight over 6-month period
Example: 180-pound person should lose 18 lb/6 months = 3 lb/month, ¾ lb/week
To lose 1 pound of body fat, need 3,500-calorie deficit
For a weight loss of ½ to 1 lb/week, need to decrease daily calories by 250 to 500 calories
Fad diets promise dramatic results but may carry risks
© 2015 Pearson Education, Inc.
31
How Can You Lose Weight Healthfully?
Successful long-term weight loss requires changes in diet, physical activity, behavior
Eat smart, because calories count: add satiation to low-calorie meals by including higher-volume foods
Eat more vegetables, fruit, and fiber
Include some protein and fat in your meals
Protein increases satiety most
Fat slows movement of food from stomach into intestines
Choose lean meat, skinless chicken, fish, nuts, unsaturated oils
© 2015 Pearson Education, Inc.
Three Pieces of the Long-Term Weight-Loss Puzzle
© 2015 Pearson Education, Inc.
Figure 10.8
33
Adding Volume to Your Meals
© 2015 Pearson Education, Inc.
Figure 10.9
Control of Appetite: Hunger and Satiety
© 2015 Pearson Education, Inc.
35
© 2015 Pearson Education, Inc.
Table 10.3
36
The Volume of Food You Eat
© 2015 Pearson Education, Inc.
Figure 10.10
37
Practical Nutrition Tips Video: Coffee Shop
© 2015 Pearson Education, Inc.
38
Practical Nutrition Tips Video: 100 Calories
© 2015 Pearson Education, Inc.
39
How Can You Lose Weight Healthfully?
Use MyPlate as a weight-loss guide
High volume of fruits, vegetables, whole grains, some lean protein, modest amounts of fat
Diet should contain variety of foods from all food groups
Replace higher-calorie foods with lower-calorie options from each food group.
Example: replace full-fat dairy with nonfat products
Replace sodas with water
© 2015 Pearson Education, Inc.
40
How Can You Lose Weight Healthfully?
Move to lose
45 minutes/day of moderate-intensity activities can prevent becoming overweight and aid in weight loss
10,000 steps/day can reduce risk of becoming overweight
Break bad habits
Behavior modification: change behaviors that contribute to weight gain or impede weight loss
Techniques include keeping food log, controlling environmental cues that trigger eating, managing stress
© 2015 Pearson Education, Inc.
41
© 2015 Pearson Education, Inc.
Table 10.4
42
Food Log
© 2015 Pearson Education, Inc.
Figure 10.11
43
Evaluating Popular Diets
Reduction of calories, not composition of diet, is key to weight loss
People who diligently adhere to diets lose the most weight
High dropout rates for most extreme diets (Atkins and Ornish diets)
Beware of fad diet claims and hype:
"It's carbs, not calories, that make you fat!"
"Lose seven pounds in one week!"
Celebrity-endorsed miracle weight-loss products
"Natural" substances help lose weight without risk
© 2015 Pearson Education, Inc.
44
Discussion Questions
Why do you think the Weight Watchers program has been so successful? What role does social support play in the program?
What are some recommendations or strategies for those who want to lose weight but cannot afford Weight Watchers?
© 2015 Pearson Education, Inc.
Best Diet Plan Apparently Works
45
How Can You Maintain Weight Loss?
Weight cycling (repeated gain and loss of body weight) is common result of fad diets
Weight loss can be maintained if healthy habits used during weight loss are maintained
New, lower weight requires fewer calories to maintain weight
Physical activity can close the "energy gap" easier than further reducing caloric intake
© 2015 Pearson Education, Inc.
46
Discussion Questions
Discuss the practical methods used for keeping weight off.
Discuss psychological factors or contributors for the inability to maintain weight loss.
What tips would you give someone who wanted to lose weight safely and to maintain weight loss?
© 2015 Pearson Education, Inc.
20/20: Half Their Size - Losing Weight and Keeping it Off
47
Extreme Measures for Extreme Obesity
BMI > 40 = extreme obesity
High risk of heart disease, stroke, dying
Requires aggressive weight-loss treatment, including very-low-calorie diets, medications, and/or surgery
Very-low-calorie diets (< 800 calories) are short-term and must be medically supervised
Medications such as Orlistat, Belviq, and Qsymia can't replace a lower-calorie diet, physical activity, and behavior modification
© 2015 Pearson Education, Inc.
48
© 2015 Pearson Education, Inc.
Diet Dream Drug? Hope or Hype: Pros and Cons of Alli
49
Extreme Measures for Extreme Obesity
Gastric bypass and gastric banding result in higher levels of satiety and lower levels of hunger
Results in dramatic weight loss and reduction of hypertension, diabetes, high blood cholesterol, and sleep apnea
Small risk of gallstones, death from surgery
Liposuction is performed for cosmetic reasons
Fat may reappear; results are not permanent
Complications such as infections, scars, swelling
© 2015 Pearson Education, Inc.
50
Gastric Bypass and Gastric Binding
© 2015 Pearson Education, Inc.
Misc 10.14
51
How Can You Gain Weight Healthfully?
Gaining weight for the underweight is as challenging as losing weight is for the overweight
Need to add at least 500 calories to daily energy intake for gain of 1 pound/week
Choose more energy-dense but nutritious foods from each food group
Examples: waffle instead of toast, coleslaw instead of cabbage
Eat more snacks during day to add more calories
© 2015 Pearson Education, Inc.
52
More- and Less-Energy-Dense Food Choices, by Food Group
© 2015 Pearson Education, Inc.
Figure 10.12
53
What Is Disordered Eating and What Are the Warning Signs?
Disordered eating: abnormal and potentially harmful eating behaviors that do not meet specific criteria for eating disorders
Eating disorders: psychological illnesses that involve specific abnormal eating behaviors and other factors
In United States, about 20 million women and 10 million men struggle with eating disorders at some point in life
Most are adolescent or young adult white, middle/upper-middle-class females, but increasing among males, minorities, other age-groups
© 2015 Pearson Education, Inc.
54
© 2015 Pearson Education, Inc.
Table 10.5
55
What Is Disordered Eating and What Are the Warning Signs?
No single factor causes eating disorders
Sociocultural factors
Desire/social pressure to be thin or "cut"
Genetic factors
Eating disorders "run in families"
Psychological factors
Depression, anxiety, perfectionism, sense of control contribute
© 2015 Pearson Education, Inc.
56
Factors That Contribute to Eating Disorders
© 2015 Pearson Education, Inc.
Figure 10.13
57
What Is Disordered Eating and What Are the Warning Signs?
Anorexia nervosa results from severe calorie restriction
Self-starvation and excessive weight loss
Intense fear of being "fat"
Distorted body image: see oneself as fat when underweight
Health consequences: electrolyte imbalance (low blood potassium) can be fatal
Other risks: decrease in heart rate and blood pressure, lanugo (downy hair), osteoporosis
© 2015 Pearson Education, Inc.
58
What Is Disordered Eating and What Are the Warning Signs?
Bulimia nervosa involves cycle of binge eating and purging
Purging can include self-induced vomiting; excessive exercising; strict dieting or fasting; abuse of diet pills, laxatives, diuretics
Vomiting can cause tears in esophagus, swollen parotid glands, tooth decay, gum disease, broken blood vessels in eyes
Potentially fatal electrolyte imbalance can result
© 2015 Pearson Education, Inc.
59
What Is Disordered Eating and What Are the Warning Signs?
Binge eating disorder involves compulsive overeating (without purging)
Eat in secret, feelings of shame
Health effects are those associated with obesity
High blood pressure, cholesterol levels
Risk of heart disease, type 2 diabetes, gallbladder disease
© 2015 Pearson Education, Inc.
60
What Is Disordered Eating and What Are the Warning Signs?
Other disordered eating behaviors can be harmful
Orthorexia: "healthy or righteous eating"
Fixation on eating the "right" foods
Night eating syndrome: combination eating, sleep, mood disorder
Person consumes most calories after evening meal, wakes up at night to eat
Pica: desire to consume nonnutritive substances (clay, dirt, chalk)
Can cause medical complications
© 2015 Pearson Education, Inc.
© 2015 Pearson Education, Inc.
Extreme Healthy Eating - What is Orthorexia?
62
© 2015 Pearson Education, Inc.
63
What Is Disordered Eating and What Are the Warning Signs?
There are some common signs of disordered eating
Hair loss
Significant/sudden weight changes
Russell's sign: scar tissue on knuckles of fingers used to induce vomiting (bulimia nervosa)
Avoiding social situations where food is present
Weighing often, obsessively counting calories
Denial of problem
© 2015 Pearson Education, Inc.
64
What Is Disordered Eating and What Are the Warning Signs?
Eating disorders can be treated
Multidisciplinary team approach is most effective
Psychological, medical, and nutrition professionals
Nutritional approaches include:
Identifying binge triggers, safe and unsafe foods, hunger and fullness cues using food journals
Meal plans to ensure adequate calorie/nutrient intake (anorexia nervosa) or to avoid overeating (bulimia nervosa, binge eating disorder)
Best treated in early stages; no "quick fix"
© 2015 Pearson Education, Inc.
65
Discussion Questions
Discuss the signs and symptoms of EDNOS.
Discuss types of treatment used to treat EDNOS.
What are your reactions to the method of having the women in the treatment clinic eat foods that may not be the healthiest (i.e., pizza, Chinese food)? In your opinion, is this the best method of treatment? Why or why not?
© 2015 Pearson Education, Inc.
EDNOS: Most Dangerous, Unheard of Eating Disorder
66