Title: Energy Balance and Healthy Body Weight
1Energy Balance and Healthy Body Weight
Chapter 9
2Energy Balance and Healthy Body Weight
- Being both overweight and underweight present
risks to health - Extreme Obesity BMI 40 Too much fat
- Obesity BMI 30-39.9 Too much fat
- Overweight BMI 25.0 - 29.9 Too much fat
- Healthy Weight 18.5- 24.9
- Underweight BMI
3Too Little or Too Much Body Fat
- In the U.S.
- Too little body fat is not a widespread problem
- Obesity is an escalating epidemic
- In the year 2000
- 64 of U.S. adults were overweight
- 30 were obese
- One of every seven U.S. children and teenagers is
overweight
4Risks from Underweight
- Underweight people are at risk of dying
- During a famine
- When hospitalized if they go without food for
days when undergoing tests for surgery - Underweight people are at greater risk when
fighting a wasting disease - People with cancer often die from starvation, not
the cancer itself - Underweight people should gain body fat as an
energy reserve
5Risks from Overweight
- Hypertension, diabetes, heart disease
- Abdominal hernias, arthritis, complications in
pregnancy and surgery, flat feet, gallbladder
disease, gout, high blood lipids, liver
malfunction, respiratory problems, sleep apnea,
some cancers, varicose veins, high accident rate - Only tobacco contributes to more preventable
diseases and premature deaths
6Overweight
- Central Obesity
- Fat within the central abdominal area of the body
(waist circumference) - Increases the risk of diabetes, stroke,
hypertension, coronary artery disease - Apple Shape (visceral fat)
- Pear shape (subcutaneous fat)
70
8Risks from Overweight?
- Who is prone to central obesity
- Men and postmenopausal women
- Smokers
- Those with high alcohol intake
- Those who are physically inactive
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10Risks from Overweight
- Social and Economic Costs of Obesity
- Fat people are more likely to be judged on their
appearance rather than their character - Our society places enormous value on thinness,
especially for women - harder to get job, insurance, higher clothing
costs - Prejudice often stereotypes obese people as lazy,
stupid and self indulgent - Obese people suffer emotional pain when treated
with hostility and contempt
11What Is The Bodys Energy Balance
- When more food energy is consumed than is needed,
excess fat accumulates in the fat cells of the
bodys adipose tissue - Energy Balance
- Energy in Energy out
- energy in foods and beverages
- energy out lifestyle and metabolism
12The Bodys Energy Balance
- Estimated Energy Requirements (EER) on DRI chart
- Apply only to the characteristics of the
reference man and woman - Reference man active physical activity level,
22.5 BMI, 510, 154 lb. - Reference woman active physical activity
level, 21.5 BMI, 54, 126 lb.
13The Bodys Energy Balance
- Taller people have a greater surface area
require more energy - Older people need less energy than younger
people- 5 for each decade beyond the age of 30
years - Due to a slower metabolism and reduced muscle
mass
14How Many Calories Do I Need Each Day?
0
- Energy output
- Basal metabolism
- Sum total of energy expended on all of the
involuntary activities needed to sustain life - Excludes digestion
- Voluntary activities
- Thermic effect of food
- 5-10 of a meals energy is expended in
stepped-up metabolism in the 5 hours after a meal
15How Many Calories Do I Need Each Day?
- Basal metabolic rate (BMR)
- Varies from person to person
- Varies with activity level
- Positively correlates with thyroxin secretion
- Lowest during sleep
- Lean tissue has a higher BMR than fat tissue
16How Many Calories Do I Need Each Day?
- Estimated Energy Intake
- EER is based on gender, age, weight , height, and
physical activity - This was built into the Food Pyramid.
- The equation is in your text book.
17Body Weight versus Body Fatness
- Body Mass Index (BMI)
- Correlates with body fatness
- Used to evaluate health risks associated with
underweight or overweight - In general, for adults
- Overweight is defined as a BMI of 25.0 - 29.9
- Obesity as BMI 30
- Body Mass Index (BMI)
- BMI (weight in kg)/(height in m2)
- BMI ((weight in lb)/(height in in2)) x 705
18Body Weight versus Body Fatness
0
- BMI values fail to distinguish between how much
of a persons weight is fat and where the fat is
located. - This limits the value of BMI with
- Athletes highly developed muscle falsely
increases BMI - Pregnant and lactating women increased weight is
normal during childbearing - Adults over 65 because BMI values are based on
data collected from younger people and because
people shrink with age
19Body Weight versus Body Fatness
- Methods used to Measure Body Composition and Fat
Distribution - Anthropometry
- Fat fold tests
- Waist circumference
- Density
- Underwater weighing
- Conductivity Radiographic techniques
- Bioelectrical impedance
- Dual energy X-ray absorptiometry (DEXA)
- Radiographic techniques
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21Body Weight versus Body Fatness
- How Much Body Fat Is Ideal?
- Varies with gender, age, stage of life
- Percent body fat
- Man of healthy weight 12 - 20
- Overfat greater than 22
- 25 if over 40 years
- Female of healthy weight 20 - 30
- Overfat greater than 32
- 35 if over 40 years
22Obesity
- Factors that correlate with obesity
- Birth order, Number of brothers
- Divorced/single parents, Nonprofessional parents
- Unemployed parents
- Early menstruation
- Ethnicity
- Exposure to a variety of foods
- Fast-food consumption
- Fat, protein, carbohydrate intake-too much
food!!! - Increased wealth (In developing nations)
- Less leisure time
- International travel
- Geographic location
23Obesity
- More factors that correlate with obesity
- Lower education level
- Lower social class
- Maternal famine
- Obesity during gestation
- Meal skipping, Meals eaten away from home
- Napping habits, Sleep deprivation
- Reduced alcohol intake, Increased alcohol intake
- Sedentary behavior, Television watching
- Substandard housing
- Everything!!! But mostly eating too much!!!!
24Eating Behavior
- Eating behavior is regulated by mechanisms that
stimulate eating and mechanisms that signal the
body to stop eating - 1 Hunger and Appetite
- 2 Seek Food and Eat
- 3 Keep Eating
- 4 Satiation, End Meal
- 5 Post Absorptive Influences
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26Eating Behavior
- What is Hunger?
- Sensation that signals a need for food
- Occurs roughly 4-6 hours after eating
- After the food has left the stomach and much of
the nutrient mixture has been absorbed - Triggered by a contracting empty stomach and
empty small intestine - The stomach hormone ghrelin produced between
meals signals the hypothalamus (brain) to
simulate eating - The hunger response quickly adapts to changes in
food intake (to larger or smaller quantities of
food) - Food deprivation can lead to overeating to
overcompensate for the calories lost during
deprivation
27Eating Behavior
- What is Appetite?
- The psychological desire to eat
- Can be experienced without hunger
- The sight and smell of food can stimulate the
brains endorphins, molecules that create an
appetite despite an already full stomach - Illness or stress may result in the loss of
appetite in a person in physical need of food
28Eating Behavior
- Other factors affecting appetite
- Hormones
- Inborn appetites (for salt, sweet, fat)
- Learned preferences, aversions, timings
- Customary eating habits
- Social interactions (companionship)
- Some disease states (cold flu)
- Appetite stimulants, depressants, mood-altering
drugs - Environmental conditions (hot and cold)
29Eating Behavior
- What are Satisfaction and Satiety?
- The perception of fullness that builds throughout
a meal - The stomach sends signals to the brain to tell it
that its full - The brain also detects nutrients in the blood
- Hunger strongly stimulates eating behavior
- Satiation and satiety exert weaker control over
food intake and can be ignored - (keep eating)
30Eating Behavior
0
- Leptin A Satiety Hormone
- Leptin
- An appetite-suppressing hormone
- Produced by adipose tissue
- Travels to the brain
- Directly linked to appetite and body fatness
- Gain of body fatness stimulates leptin production
- Reducing food consumption resulting in fat loss
- Loss of body fat reduces leptin secretion
- Increasing appetite
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32Why Did I Eat That?
- Energy Nutrients and Satiety
- At least 15 studies show that a low-glycemic
index diets reduced or delayed hunger - 16 studies have found the opposite or no effect
- Showed that diets based on refined grains are
just as satisfying as diets based on low-glycemic
index diets
33Why Did I Eat That?
- Of the energy-yielding nutrients, protein may be
the most satiating - May account for the popularity of high-protein
weight-loss diets - Fat is also known for its satiety effects
- Protein and fat trigger the release of an
intestinal hormone that slows stomach emptying
and prolongs feelings of fullness - Satiety is also associated with
- High-fiber foods
- Water
- Foods that have been puffed up from air
- ???What works for you???
34Inside-the-Body Causes of Obesity
- Selected Metabolic Theories of Obesity
- Attempt to explain the ease with which people
gain/lose weight when eating more/less food
energy than they use
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36Causes of Obesity
- Genetics
- Decrease energy expended in activities required
for daily living - Inactivity
- Food Price, Availability, and Advertising
- High-calorie fast foods are relatively
inexpensive, widely available - A steady diet of them correlates with obesity
- External Cues to Overeating
- eat even when not hungry
- Loneliness, Yearning, Craving, Addiction,
- Compulsion, Depression, Time of day
- ???Do thin people deal with these things??
37Causes of Obesity
- End of Story?
- There is no clear evidence as to which factor(s)
bears the greatest responsibility for obesity - For most people, the best way to obtain a healthy
body weight is to - Maintain a proper diet
- Engage in daily physical activity
- Practice behavior modification
- Can low price, advertising and availability of
healthy foods attract consumers????
38Activity for Healthy Body Weight
- Moderate exercise is defined by NIH as using 150
calories per day (1,000 calories per week) - Exercise does not have to be excessive to achieve
fat loss - The DRI definition of an active lifestyle
requires walking for 1 hour per day - Is this enough activity?????
39Activity for Healthy Body Weight
- Physical activity for weight loss or maintenance
- Moderate activities
- Use large muscle groups
- Increase in physical activity
- Adopt informal strategies to be more active
- Physical activity for building body mass
- Strength-building exercises
- Perform exercises with increasing intensity,
resistance training
40Weight Loses and Gains
- Moderate Weight Loss versus Rapid Weight Loss
- When energy input is less than energy output, the
body draws on its energy stores - With exercise, moderate calorie restriction and a
balanced diet, a body will use its stores of fat
41How the Body Loses and Gains Weight
- Rapid wt loss
- The Bodys Response to Fasting
- Less than 1 day into the fast liver glycogen
stores are exhausted - Protein is broken down and converted to
carbohydrate to meet the brains need for glucose - If left unchecked the breakdown of protein
(muscle of the heart, skeletal muscle, liver,
etc) results in death within about 10 days - To prevent this, the body converts fat into
ketone bodies, a fuel the nervous system can
adapt to using
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43How the Body Loses and Gains Weight
- Ketosis
- In ketosis, instead of breaking down fat to CO2
and H2O, the body takes partially broken-down fat
fragments and combines them to form ketone bodies - Some amino acids that cannot be converted to
glucose, are converted to ketone bodies - After about 10 days of fasting, most of the
nervous systems energy needs are met by ketone
bodies
44How the Body Loses and Gains Weight
- Fasting may harm the body
- Ketosis upsets the acid-base balance of the blood
- Promoting excessive mineral loss in the urine
- In as little as 24 hours of fasting, the
intestinal lining deteriorates - Food deprivation leads to overeating/ binging
when food becomes available - Fasting breaks down the bodys lean tissues
- The body adapts to fasting by slowing its
metabolic rate
45How the Body Loses and Gains Weight
- The Bodys Response to a Low-Carbohydrate Diet
- Responses are similar to those of fasting
- As carbohydrate runs low the body breaks down fat
and protein for energy and ketones form to feed
the brain - To prevent this the DRI for carbohydrates is set
at 130 grams/day 45-65 - Initial weight loss is the water and glycogen
losses when carbohydrate is lacking - Loss of appetite accompanies any low-calorie diet
46How the Body Loses and Gains Weight
- Weight Gain Energy-yielding nutrients contribute
to excess body stores - Protein excess amino acids have their nitrogen
removed and are used for energy or converted to
glucose or fat - Fat fatty acids can be broken down for energy or
stored as fat with great efficiency glycerol
enters a pathway similar to carbohydrate - Carbohydrate (other than fiber) glucose may be
used for energy or excess may be converted to
glycogen or fat and stored - Alcohol used for fuel or converted to body fat
and stored as visceral fat - Excess consumption of any food will be turned to
fat within hours
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48Popular High-Protein, Low-Carbohydrate Diets
- Laboratory studies have shown that, when energy
intake is the same, there is no difference in
weight loss on a high-protein, low-carbohydrate
diet or a lower-protein, higher-carbohydrate
diet
49Popular High-Protein, Low-Carbohydrate Diets
- High in saturated fat
- Increased cardiovascular disease risk
- Increased risk of breast cancer
- Low Carbohydrate Intake
- Mixed results with regard to cardiovascular risk
- Missing nutrients from the diet
- Chronic ketosis
50What Strategies Are Best for Weight Loss?
- Dietary Guidelines for Americans 2005
- Energy in must be less than energy expended
- Calorie intake must decrease to attain weight
loss - Diet based on all the food groups may be the
safest and easiest in the long term - Increase physical activity
51What Diet Strategies Are Best for Weight Loss?
- Setting Goals
- For an overweight person
- First reasonable goal may be to prevent weight
gain - Reduce body weight by 5-10 over the course of a
year - Recognize that maintenance is often more
difficult than weight loss - Keep Records
- A tool for spotting trends and identifying areas
in need of improvement - Measure waist circumference to track changes in
central obesity
52What Diet Strategies Are Best for Weight Loss?
- Realistic Calorie Intakes
- Energy intakes lower than 800 calories are not
good for achieving lasting weight loss, and may
promote eating disorders - Diets for weight management should provide the
DRI recommended ranges - Carbohydrate 45 - 65 of total calorie intake
- Fat 20 - 35 of total calorie intake
- Protein 10 - 35 of total calorie intake
53What Diet Strategies Are Best for Weight Loss?
- Fats
- Avoid saturated and trans fats
- Include enough of the health-supporting fats to
provide satiety but not so much as to oversupply
calories olive, canola oil - Protein
- Choose lean meats or other low-fat protein
sources - Limit these foods but dont eliminate them
- Carbohydrates
- Choose whole grains and starchy vegetables rather
than refined grains, added fats, and sugars - High-fiber, unprocessed or lightly processed
foods offer bulk and satiety for fewer calories
than quickly consumed refined foods
54What Diet Strategies Are Best for Weight Loss?
- Alcohol
- Limit intake
- Alcohol provides calories but no nutrients
- Alcohol reduces inhibitions and can sabotage a
dieters plans - Portion Sizes
- Be aware of portions in restaurants and food
packages - Use a measuring cup to learn portion sizes
- Learn fat grams- they add calories more quickly
than carbohydrate or protein -
55Demonstration Diet
56What Diet Strategies Are Best for Weight Loss?
- People who eat small, frequent meals are reported
to be more successful at weight loss and weight
management - Make sure that hunger, not appetite, prompts
eating - Eat regularly, before becoming hungry
- Eat the entire meal
- Save calorie-free or favorite foods or beverages
for a planned snack - Eat breakfast
- Those who consume the majority of their calories
after 600 p.m. often find it harder to lose
weight
57Physical Activity for Weight Loss
- 30 - 60 minutes of moderate physical activity
per day are needed to prevent weight gain and
support weight loss - Diet, in combination with exercise, promotes fat
loss, promotes muscle retention, inhibits weight
gain - Exercise helps people follow diet plans more
closely - Exercise reduces abdominal obesity
- Improves BP, insulin resistance, heart and lung
fitness even without weight loss
58Physical Activity for Weight Loss
- Benefits of Exercise
- Short-term it increases energy expenditure
- Long-term increase in BMR
- increase lean tissue
- Improved body composition
- Appetite control??
- Stress reduction and control of stress eating
- Physical and psychological well-being
- Improved self-esteem
- Any activity is better than no activity
- Expenditure of at least 2,000 calories per week
in physical activity promotes weight management
59What Strategies are Best for Weight Gain?
- An underweight person should not necessarily try
to gain weight - If you are healthy, maintain your current weight
- Examples of those who may be at health risk from
a too-low body weight - Physician has advised you to gain weight
- You are excessively tired
- You are unable to keep warm
- You fall into the underweight category of the BMI
- You are a woman who has missed at least three
consecutive menstrual periods
60What Strategies are Best for Weight Gain?
- To Gain Muscle and Fat
- Best achieved through physical activity
especially strength training in combination with
a high-calorie diet - Diet alone can bring about weight gain in the
form of fat - Good for someone with a wasting disease
- Gaining a pound of muscle and fat requires an
intake of 3,500 extra calories
61What Strategies are Best for Weight Gain?
- Weight Gain Supplements
- Most weight-gain supplements are useless
- No benefits beyond adding calories and a few
nutrients - Items such as instant breakfast powders or milk
flavorings can do the same thing for less money - Tobacco (avoid)
- Suppresses appetite
- Makes taste buds less sensitive
62What Strategies are Best for Weight Gain?
- Choose Foods with High Energy Density
- Chose nutritious energy-dense foods, for example
- Peanut butter in place of lean meat
- Avocado in place of cucumber
- Increase portion sizes
- Expect to feel full
- Eat frequently
- Make foods appealing
63Drugs and Surgery to Treat Obesity
- BMI30 and those with elevated disease risk may
benefit from prescription medication, along with
diet, exercise, and behavior therapy, to lose
weight - Extreme obesity (BMI40 BMI35 with coexisting
disease) surgery may be an option - Reduction of stomach size
- Not a cure for obesity
- Some do not lose the expected pounds
- Some who initially lose weight gain it back
through the course of time
64Drugs and Surgery to Treat Obesity
- Gastric surgery- Long-term safety depends on
compliance with diet - Complications following surgery include
- Infections
- Nausea
- Vomiting
- Dehydration
- Vitamin and mineral deficiencies
- Psychological problems
- Such surgery requires lifelong medical
supervision
65Drugs and Surgery to Treat Obesity
- Liposuction
- Cosmetic procedure-surgical
- There can be serious complications, including
death - Herbal Products
- For many, their effectiveness and safety have not
been proved - Natural does not mean safe
- Belladonna, hemlock, and sassafras all contain
toxins - Ephedra (ma huang) contains ephedrine
- weight loss
- Side effects--Cardiac arrest, abnormal heart
beat, hypertension, stoke, seizure, death - FDA has banned sales, available on internet
- TRIAC
- Sold as diet aid
- Hormone that interferes with thyroid function
- Has caused heart attack and stroke
- Marketed as dietary supplements and escape FDA
scrutiny
66Drugs and Surgery to Treat Obesity
- Herbal laxatives containing senna, aloe, rhubarb
root, cascara, castor oil, or buckthorn - Sold as dieters tea
- Can cause temporary water loss of 1-2 pounds
- Side effects include nausea, vomiting, diarrhea,
cramping, fainting, possible deaths
67Weight Control
- Weight loss strategy
- Behavior Modification
- Learning to say No might be the first habit to
establish - Learning not to clean your plate is another
behavioral change - Change enviornment
68Eating Disorders
- 5 million people in the U.S. suffer from eating
disorders - Anorexia nervosa
- Bulimia nervosa
- Binge eating disorder
- 85 of eating disorders start during adolescents
69Eating Disorders
- Causes of eating disorders
- Excessive pressure to be thin is partly to blame
- When low body weight becomes a goal, people begin
to view normal, healthy body weight as too fat - Excessive dissatisfaction with body weight or
feeling fat
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71Eating Disorders
- Eating Disorders in Athletes
- Athletes and dancers are at special risk of
eating disorders - Female athlete triad
- Disordered eating, Amenorrhea, Osteoporosis
- Female athletes often compare themselves to
unsuitable weight standards - An ultra-slim appearance has long been considered
desirable in activities such as dancing,
gymnastics, and figure skating - Males have some of the same physical problems
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73Eating Disorders
- Practices by wrestlers trying to make weight
can compromise their abilities and endanger their
lives - Male athletes are susceptible to weight-gain
problems - Athletes with well-muscled bodies see themselves
as underweight and weak - Such distorted body image leads to frequent
weighing, excessive exercise, overuse of special
diets or protein supplements, or even abuse of
steroid drugs
74Eating Disorders
- Characteristics of Anorexia Nervosa
- Most anorexia nervosa victims come from middle or
upper-class families - Males account for 5 to 10 of cases
- The incidence among male athletes and dancers may
be higher - Central to its diagnosis is a distorted body
image that overestimates body fatness - Family attitudes contribute to eating disorders
- Families of anorexics are likely to be critical
and to overvalue outward appearances rather than
inner self-worth
75Eating Disorders
- Anorexics may be perfectionists
- Respectful of authority polite, controlled,
rigid - Rejecting food is a way of gaining control
- Anorexia Nervosa Self-Starvation
- Discipline is used to strictly limit portions of
low-calorie foods - Hunger is denied
- Become accustomed to little food
- Calorie contents of foods are memorized
- Calorie expended during exercises are memorized
76Eating Disorders
- Anorexia Nervosa
- Causes the same damage as classic protein-energy
malnutrition - Body tissues are depleted of needed fat and
protein - In young people, growth ceases and normal
development stops - So much lean tissue is lost that BMR slows for
self preservation - In athletes
- The loss of lean tissue impairs performance
- The heart pumps inefficiently and irregularly
- Heart muscle becomes weak and thin
- Blood pressure falls
- Electrolytes that help to regulate heart beat go
out of balance - Many deaths are due to heart failure
77Eating Disorders
- Treatment of Anorexia Nervosa
- Requires a multidisciplinary approach
- Low risk clients may benefit from
- Family counseling
- Cognitive therapy
- Behavior modification
- Nutrition guidance
- High risk clients may also need
- Other forms of psychotherapy
- Supplemental formulas to provide energy and
nutrients - Drugs are commonly prescribed, but their
usefulness is limited
78Eating Disorders
- Few anorexics seek treatment on their own
- Denial makes treatment difficult
- Many relapse into abnormal eating behaviors
- Anorexia nervosa has a high mortality rates among
psychiatric disorders
79Eating Disorders
- Bulimia Nervosa
- More common then anorexia nervosa
- People often suffer in secret and may deny the
existence of a problem - More men suffer from bulimia nervosa than from
anorexia nervosa - However, more common in women
80Eating Disorders
- Binge Eating and Purging
- Food is not consumed for its nutritional value
- Eating is accelerated by hunger from previous
caloric restriction - Nearly 1,000 extra calories are consumed at a
time - There may be several binges in a day
- Typical binge foods
- Easy-to-eat foods
- Low-fiber
- Smooth-texture
- High-fat
- High-carbohydrate
81Eating Disorders
- After the binge
- Hands may be scraped raw against the teeth during
induced vomiting - Swollen neck glands and reddened eyes from
straining to vomit - Bloating, fatigue, headache, nausea, pain
- Vomiting causes
- Irritation and infection of the pharynx,
esophagus, salivary glands - Erosion of the teeth and dental caries
- The esophagus or stomach may rupture or tear
- Overuse of emetics (cause vomiting) can lead to
death by heart failure
82Eating Disorders
- Bulimia Nervosa Physical and Psychological
Problems - Fluid and electrolyte imbalances are caused by
vomiting or diarrhea - They can cause abnormal heart rhythms and injury
to the kidneys, UTIs can lead to kidney failure - Unlike anorexics, bulimics are aware that their
behavior is abnormal, and they are ashamed of it - Bulimics are less likely to be in denial and more
likely to recover
83Eating Disorders
- Treatment of Bulimia Nervosa
- To regain control over food and establish regular
eating patterns requires adherence to a
structured eating plan - Regular exercise may be of benefit
- Restrictive dieting is forbidden
- Steady maintenance of weight
- Prevention of relapse into cyclic gains and
losses - Learning to consistently eat enough food to
satisfy hunger needs - 50 of females recover completely after 5 - 10
years with or without treatment - Antidepressant medication may be of benefit
84Eating Disorders
- Binge Eating Disorder
- Up to 50 of all people who restrict eating to
lose weight periodically binge without purging - Obesity itself does not constitute an eating
disorder - Binge eating behavior responds more readily to
treatment than other disorders - Successful treatment improves physical health,
mental health, and the chances of breaking the
cycle of rapid weight losses and gains
85Eating Disorders
- Eating Disorders in Society
- Eating disorders have many causes
- Sociocultural
- Known only in developed nations
- Become more prevalent as wealth increases and
food becomes plentiful - Psychological
- Heredity
- Probably neurochemical unbalance
- Society sets unrealistic ideals for body
weight-Especially for women