Transcript Chapter 5 - Academic Resources at Missouri Western

Outline:
1.Overweight vs.
Obesity
2.Diet Crazes
3.Eating Disorders
4.The Physiology of
Weight Loss
5.Diet and Metabolism
6.Exercise: The Key to
Weight Management
7.Losing Weight the
Sound and Sensible Way
8.Behavior Modification
& Adherence to a Weight
Management Program
9.The Simple Truth
Chapter 5
Weight Management
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Weight Management
• Obesity has become an epidemic in most
developed countries around the world
• The WHO estimates 35% of the adult
population in industrialized nations is
obese
• The obesity level is the point at which
excess body fat can lead to serious health
problems
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Average weight of Americans between
1963-1965 and 1999-2002
• Obesity and
overweight have
dramatically increased
as a direct result of
physical inactivity and
poor dietary habits
• Average weight of
American adults
between ages 20 and
74 has increased by
25 lbs. or more since
1965
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Percentage of the adult population that is overweight (BMI ≥
25) and obese (BMI ≥ 30) in the United States
• More than 66% of
U.S. adults are over
overweight and 32%
are obese
• Between 1960 and
2002, the prevalence
of adult obesity
increased from about
13% to 30%
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Obesity trends in the United States 1985-2007 based on
BMI ≥ 30 or 30 pounds overweight
• Rates of obesity
increased in the 1990s
• No state reported an
obesity rate above
15% before 1990
• By 2007, only one
state had a prevalence
of less than 20%
• Thirty states had a
prevalence ≥ 25%
• Three of these states
had a rate above 30%
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Weight Management
• About 44% of all women and 29% of all
men are on a diet at any given moment
• People spend about $40 billion yearly
attempting to lose weight
– over $10 billion to weight reduction centers
– $30 billion to diet food sales
• About $100 billion spent yearly to treat
obesity-related diseases
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Weight Management
• Excessive body weight and physical
inactivity are the second leading cause of
preventable death in the U.S. (over
112,000 deaths year)
• Obesity is more prevalent than smoking,
poverty, and problem drinking
• Obesity and unhealthy lifestyles are the
most critical public health problems of the
21st century
• Health risks increase at a BMI over 25 and
are enhanced at a BMI over 30
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Health Consequences of Excessive
Body Weight
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Overweight versus Obesity
• Overweight: A chronic disease
characterized by a body mass index (BMI)
greater than 25 but less than 30
• Obesity: A chronic disease characterized
by a body mass index (BMI) 30 or higher
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Tolerable Weight
• The media has the greatest influence on
people’s perception of what constitutes
ideal body weight
• Most people use fashion, fitness, and
beauty magazines to determine what they
should look like
• The “ideal” body shapes, physiques, and
proportions seen in these magazines are
rare and essentially achieved only through
airbrushing and medical reconstruction
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The Weight Loss Dilemma
• Yo-yo dieting carries as great a health risk
as being and remaining overweight
• Data show frequent fluctuations (up or
down) in weight increase the risk of dying
from cardiovascular disease
• Quick-fix diets should be replaced by a
slow, permanent weight loss program
• Individuals gain the benefits of
recommended body weight when they
reach that weight and stay there
throughout life
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The Weight Loss Dilemma
• Only about 10% of people who begin a
traditional weight loss program without
exercise lose the desired weight
• Only 5 in 100 keep the weight off because
the body is highly resistant to permanent
weight changes through calorie
restrictions alone
• Traditional diets fail because few of them
incorporate permanent behavioral changes
in food selection and overall increase in
physical activity and exercise
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Diet Crazes
• Fad diets continue to appeal to people of all
shapes and sizes
• These diets may work for a while but their
success is usually short lived
• Fad diets claim that dieters will lose weight by
following all instructions
• Very low calorie diets generate a metabolic
imbalance by creating a nutritional deficiency
• Much of the weight lost is in the form of water
and protein, not fat
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Low-Carb Diets
• Low-carbohydrate/high-protein (LCHP) diets have
been very popular
– The intake of carbohydrate-rich foods--bread, potatoes,
rice, pasta, cereals, crackers, juices, sodas, sweets
(candy, cookies, cake), fruits and vegetables--is limited
– Dieters can eat all they want of protein-rich foods
including steak, ham, chicken, fish, bacon eggs, nuts,
cheese, tofu, high-fat salad dressings, butter, and small
amounts of a few fruits and vegetables
• These diets are high in fat
• Examples are the Atkins Diet, the Zone, Protein
Power, the Carb Addict’s Diet, the South Beach
Diet, Sugar Busters
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Low-carbohydrate/high-protein diets create nutritional
deficiencies and contribute to the development of
cardiovascular disease, cancer, and osteoporosis
• Without fruits, vegetables,
whole grains, high-protein
diets lack many vitamins,
minerals, antioxidants,
phytonutrients, and fiber
that protect against
various ailments and
diseases
• Long-term adherence to a
LCHP diet may increase
one’s risk for heart
disease, cancer, and
osteoporosis
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Low-Carb Diets
• Side effects associated with LCHP diets
include weakness, nausea, bad breath,
constipation, irritability, lightheadedness,
fatigue
• Your doctor should know if you go on a
LCHP diet for longer than a few weeks so
that your blood lipids, bone density, and
kidney function can be monitored
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Low-Carb Diets
• Adding extra protein (10-15 grams) to a
weight loss program can suppress hunger
• Dieters are less hungry when protein
intake is increased to 30% of total
calories, fat is 20%, and carbohydrates
stay at 50% of total calories
• 10-15 grams of protein is equivalent to
one and a half ounces of lean meat, two
tablespoons of natural peanut butter,
eight ounces of plain low-fat yogurt
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Eating Disorders
• Medical illnesses that involve crucial disturbances
in eating behaviors thought to stem from some
combination of environmental pressures
• Characterized by an intense fear of becoming fat
even when the person is losing weight in extreme
amounts
• Three most common types are anorexia
nervosa, bulimia, and binge-eating disorder
• Emotional eating can also be listed as an eating
disorder
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Eating Disorders
• People with eating disorders suffer from
family and social problems
• The eating disorder becomes the coping
mechanism to avoid dealing with these
problems
• Controlling their body weight helps them
believe they are restoring some control
over their lives
• Eating disorders are common in
industrialized nations where society
encourages low-calorie diets and thinness
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Eating Disorders
• Most prevalent among people between the
ages of 25 and 50
• 40% of college-age women are struggling
with an eating disorder
• Every 1 in 10 cases occurs in men
• These cases often go unreported because
men’s role and body image are viewed
differently in our society
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Anorexia Nervosa
• An eating disorder characterized by self-imposed
starvation to achieve and maintain very low body
weight
• Affects 1% of the population in the U.S.
• Anorexics fear weight gain more than death from
starvation
• They think of themselves as being fat even when
they are emaciated because of their distorted
body image
• They are preoccupied with food, meal planning,
grocery shopping, and have unusual eating habits
• They will not stop the starvation
• They refuse to consider the behavior abnormal
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Anorexia Nervosa
• Physical changes from
weight loss and
malnutrition include:
– amenorrhea (absence
of menstruation)
– digestive problems
– sensitivity to cold
– fluid and electrolyte
imbalances (irregular
heartbeat)
– injuries to nerves and
tendons
– abnormalities of
immune function
– anemia
– growth of fine body hair
– dry skin
– lowered skin/body
temperature
– hair and skin problems
– mental confusion
– inability to concentrate
– lethargy and depression
– osteoporosis
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Anorexia Nervosa
• Diagnostic criteria for anorexia nervosa:
– Refusal to maintain body weight over a
minimal normal weight for age and height
– Intense fear of gaining weight even though
underweight
– Disturbance in perception of one’s body
weight, size, or shape; undue influences of
body weight or shape on self-evaluation, and
denial of seriousness of current low body
weight
– Amenorrhea
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Anorexia Nervosa
• The disorder is 100% curable although it has the
highest mortality rate of all psychosomatic
illnesses--20% die as a result of their condition
• Treatment usually requires professional help
• Therapy is a combination of medical and
psychological techniques to restore proper
nutrition, prevent medical complications, and
change the environment or events that triggered
the disorder
• It can go undetected because thinness and
dieting are socially acceptable
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Bulimia Nervosa
• An eating disorder characterized by a pattern of binge
eating and purging in an attempt to lose weight and
maintain low body weight
• More prevalent than anorexia nervosa
– 1 in every 5 women on college campuses may be bulimic
– More prevalent than anorexia in males
• Bulimics are usually healthy looking, well educated, near
recommended body weight
• Bulimics enjoy food and often socialize around it
• They are emotionally insecure, rely on others, lack selfconfidence and self-esteem
• Recommended weight and food are important to them
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Bulimia Nervosa
• The binge-purge cycle can be caused by
stress or the compulsion to eat
• Bulimics periodically engage in binge
eating that may last an hour or longer
during which time they may eat several
thousand calories
– up to 10,000 calories (in extreme cases)
• After a short period of relief and
satisfaction, feelings of deep guilt, shame,
an intense fear of gaining weight emerge
• Purging seems to be the easiest answer
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Bulimia Nervosa
• Diagnostic criteria for bulimia nervosa
– Recurrent episodes of binge eating characterized by
eating in a discrete period of time an amount of food
more than most people would eat during a similar period
under similar circumstances
– A sense of a lack of control over eating during the
episode
– Practice self-induced vomiting, fasting, excessive
exercise and misuse laxatives and medications to
prevent weight gain
– Binge-purge cycle occurs on average at least twice a
week for 3 months
– Self-evaluation influenced by body shape and weight
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Bulimia Nervosa
• Medical problems
associated with bulimia
include:
– cardiac arrhythmias
– amenorrhea
– kidney and bladder
damage
– ulcers
– colitis
– tearing of esophagus or
stomach
– tooth erosion, gum
damage
– general muscular
weakness
• Bulimics know their
behavior is abnormal
and they are ashamed
so they practice in
secrecy
• A change in attitude
can prevent damage
or death
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Binge-Eating Disorder
• An eating disorder characterized by
uncontrollable episodes of eating excessive
amounts of food within a relatively short time
• Most common of the 3 main eating disorders
– About 2% of U.S. adults have binge-eating disorder in
any 6-month period
– More common in women than in men, 3 women for
every 2 men have it
• Depression, anger, sadness, boredom, worry can
trigger an episode
• Bingers are usually overweight or obese as
bingers do not purge
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Binge-Eating Disorder
• Typical symptoms include:
Eating an unusually large amount of food
Eating until uncomfortably full
Eating out of control
Eating much faster than usual during binge
episodes
– Eating alone due to embarrassment by how
much food is consumed
– Feeling disgusted, depressed, or guilty after
overeating
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Emotional Eating
• The consumption of large quantities of food to
suppress negative emotions
• Emotions include stress, anxiety, uncertainty,
guilt, anger, pain, depression, loneliness,
sadness, boredom
• People eat for comfort when they are at their
weakest point emotionally
• Comfort foods often include calorie-dense, sweet,
salty, and fatty foods
• Some foods such as chocolate help to offset
negative emotions by causing the body to release
mood-elevating opiates
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Emotional Eating
• Eating is a temporary distraction
• The following list of suggestions may help:
– Learn to differentiate between emotional and physical
hunger
– Avoid storing and snacking on unhealthy foods
– Keep healthy snacks handy
– Use countering techniques (go for a walk instead of
eating ice cream, listen to music instead of eating a
candy bar)
– Keep a “trigger” log and know what triggers your
emotional food consumption
– Work it out with exercise instead of food
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Treatment
• Treatment for eating disorders is available
through many schools’ counseling or
health center, at local hospitals,
community support groups offering
confidential help led by professional
personnel free of charge
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Energy Balancing Equation
• One pound of fat is the equivalent of
3,500 calories
• In theory, if a person requiring 3,500
calories a day decreased intake by 500
calories per day, the person should lose 1
pound of fat in 7 days
(500 x 7 = 3,500)
• When dieters balance caloric input against
caloric output, weight loss does not always
result as predicted
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Recommendation
• Daily caloric intakes of 1,200-1,500
calories provide the necessary nutrients if
they are properly distributed over the
basic food groups
• Weight loss should be gradual and not
abrupt
• Under no circumstances should a person
go on a diet that calls for a level of 1,200
calories or less for women or 1,500
calories or less for men
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Body composition changes as a result
of frequent dieting without exercise
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Exercise: The Key to Weight
Management
• A person that jogs 3 miles per exercise session 3
times a week burns 900 calories a week; 3,600
calories per month; 46,800 calories per year
• This minimal amount of exercise represents
about 13.5 pounds of fat in one year
• Many of the health benefits that people seek by
losing weight are reaped through exercise alone
• Exercise offers protection against premature
morbidity and mortality for everyone, including
people who already have risk factors for disease
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Low-Intensity vs. Vigorous-Intensity
Exercise for Weight Loss
• A greater proportion of calories burned during
low-intensity exercise are derived from fat
• The lower the intensity of exercise, the higher the
percentage of fat used as an energy source
– During low-intensity exercise, up to 50% of the calories
burned may be from fat with the other 50% from
glucose
– With intense exercise, only 30%-40% of the caloric
expenditure comes from fat
• Overall, twice as many calories can be burned
during vigorous-intensity activity, and more fat
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Low-Intensity vs. Vigorous-Intensity
Exercise for Weight Loss
• If you exercised for 30-40 minutes at moderate intensity
and burned 200 calories, 50% (100 calories) would come
from fat
• If you exercised at a vigorous intensity for 30-40 minutes
and burned 400 calories, 120-160 calories would come
from fat
• Whereas it is true that the percentage of fat used is greater
during low-intensity exercise, the overall amount of fat
used is still less during low-intensity exercise
• If you exercise at a low intensity, you would have to do so
twice as long to burn the same number of calories
• Metabolic rate remains at a slightly higher level longer after
vigorous-intensity exercise, so you continue to burn calories
after exercise
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Comparison of Energy Expenditure between 30-40 Minutes of
Low-Intensity vs. High-Intensity Exercise
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Weight Loss Myths
• Wearing rubberized sweat suits hastens
the rate of body fluid that is lost and
raises core temperature at the same time
– This combination puts a person in danger of
dehydration, which impairs cellular function
and can cause death
• Mechanical vibrators like vibrating belts
and turning rollers are worthless in a
weight control program as fat cannot be
shaken off
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Losing Weight the Sound and
Sensible Way
• Research finds that a negative caloric balance is
required to lose weight because:
– People often underestimate their intake
– People have trouble changing and adjusting to new
eating habits
– Many people take a long time to increase their activity
level enough to offset the setpoint and burn enough
calories to lose body fat
– Most successful dieters monitor their daily caloric intake
– A few people will not alter their food selection, so they
must either increase physical activity, have a negative
caloric balance, or both
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Caloric Expenditure of Selected
Physical Activities
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Losing Weight the Sound and
Sensible Way
• Breakfast is a critical meal while you are
on a weight loss program
• People who skip breakfast are hungrier
later in the day and end up consuming
more total daily calories than those who
eat breakfast
• Regular breakfast eaters have less of a
weight problem, lose weight more
effectively, and have less difficulty
maintaining weight loss
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Losing Weight the Sound and
Sensible Way
• If most of the calories are consumed
during one meal, the body may slow the
metabolism to store more calories in the
form of fat
• Eating most of the calories during one
meal causes a person to go hungry the
rest of the day, making it difficult to stick
to the diet
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Behavior Modification & Adherence to
a Weight Maintenance Program
• Make a commitment to change
• Surround yourself with people who have the
same weight loss goals you do as data indicate
that obesity can spread through “social networks”
• Gender plays a role in social networks
– A male’s weight has a greater effect on the weight of
male friends and brothers
– A woman’s weight has a greater effect on sisters and
girlfriends
– If you are trying to lose weight choose your friendships
carefully
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The Simple Truth
• There is no quick and easy way to achieve and
maintain excess body fat loss
• People have to decrease their caloric intake
moderately, be physically active, and implement
strategies to modify unhealthy eating behaviors
• Three most common reasons for relapse:
– Stress-related factors
– Social reasons
– Self-enticing behaviors
• Making mistakes is human and does not mean
failure
© 2010 Cengage-Wadsworth