Achieving a Healthy
Weight.
UNDERSTANDING BODY
COMPOSITION
1% Carbohydrates
1% Carbohydrates
6% Minerals
5% Minerals
16% Protein
12% Protein
17% Fat
61% Water
27% Fat
56% Water
Overweight Versus Obesity
Overweight refers to a body weight in excess of a
recommended range for good health.
Obesity refers specifically to having an excessive
accumulation of body fat.
BMI
An expert panel that was convened in
1998 by the National Institutes of Health
adopted the body mass index (BMI) as a
method of classifying overweight and
obesity.
BMI is a direct calculation based on
height and weight and has been
universally adopted by health
professionals to determine healthy weights
and risky weights. BMI is computed from
the following equations
BMI is computed from the following
equations
Risks Associated with Obesity
Obesity contributes to cardiovascular disease by
causing changes in the body that increase the risk
factors:
• Raises levels of LDL ("bad") cholesterol
• Raises levels of triglycerides (fats in the blood)
• Reduces levels of HDL ("good") cholesterol
• Elevates blood pressure
Obesity can aggravate liver disorders and arthritis
Obesity is often found in conjunction with diabetes
and gallbladder disease.
BMI is computed from the following
equations
Location of Fat
Fat distributed primarily in the abdominal area (called
apple-shape obesity) is characteristic of many men (but
also is present in some women). This apple-shape
obesity is linked to increased risk for coronary heart
disease, hypertension, high cholesterol, Type 2 diabetes,
and some forms of cancer.
Abdominal fat experiences much more enzyme activity,
dumping more fatty acids into the bloodstream.
Fat distributed in the lower extremities, around the hips,
buttocks, and thighs (called pear-shape obesity). Hipthigh fat activity is more stagnant, but is more difficult to
lose than is abdominal fat
Healthy People 2010
The five principles are:
Promote the recognition of overweight and obesity as
major public health problems.
Assist Americans in balancing healthful eating’ with
regular physical activity to achieve and maintain a
healthy or healthier body weight.
Identify effective and culturally appropriate interventions
to prevent and treat overweight and obesity.
Encourage environmental changes that help prevent
overweight and obesity.
Develop and enhance public-private partnerships to help
implement this vision.
WHAT CAUSES OBESITY?
energy balance
fat cells
set point
Heredity
metabolism.
Many societal factors contribute to
overweight/obesity.
Weighing the risks: Percent increase in risk by level of obesity. At BMIs
of 27 and higher, one's risk for various disorders increases significantly.
SOURCE: New England Journal of Medicine, Annals of Internal
Medicine, American Journal of Clinical Nutrition, Journal of the
American Medical Association. Circulation, 2000.
The Energy Balance Equation
The energy balance equation states that
energy input (calories consumed) must be
equal to energy output (calories expended)
for body weight to remain constant. Any
imbalance in energy input or energy output
will result in a change in body weight. If you
eat more calories daily than your body
expends in activity, you will store the
excesses as fat. If you eat fewer calories than
you burn, you will lose weight
Fat cells
The size and number of fat cells in the body determine degrees of
fatness.
Fat cells (also known as adipose cells) are storage sites for energy.
The body increases fat storage in two ways: by increasing the
number of fat cells and by increasing the size of fat cells.
As might be expected, the body increases its number of fat cells
during infancy and puberty growth spurts.
Fat cells also expand and contract as energy is stored or burned.
They can expand to two to three times their normal size, but they
cannot enlarge endlessly. At some point, new fat cells can be
created in response to the body's need to store more excess energy.
Unfortunately, once a fat cell has been created, it exists for life. Fat
cells do not seem to be destructible. An individual of normal weight
has 30 to 50 billion fat cells, while an obese person can have as
many as 60 to 100 billion fat cells.
Set-Point Theory
maintains that every individual is programmed to be a certain weight
and that the body regulates itself to maintain that "set" weight.
Studies of people in alternating states of semistarvation and gorging
have shown that once intervention ceases, they return to their
former weights.
The hypothalamus in the brain may act as a body weight thermostat,
lowering body metabolism and increasing hunger if fat levels fall
below the set point. Here is where the set-point theory and fat-cell
theory merge.
The set-point mechanism is thought to respond to signals sent out
by the fat cells as to the amount of fat in storage.
The weight at which this occurs may depend on the number of fat
cells.
Heredity
Research about genetic influences on obesity lends
some (but not total) credibility to this exclamation.
Children with obese parents do have a greater tendency
to become obese adults.
Heredity seems to influence the number of fat cells in the
body, how much fat is stored, where it is stored, and
metabolic rates. However, scientists have concluded that
genetics is responsible for only 25 percent of these
factors.
hormones may be linked to obesity. One of those
hormones, leptin, is secreted by fat cells and informs the
brain about how large or small the body's fat stores are.
As a result, the brain regulates appetite and metabolism
accordingly.
Metabolism
Every individual expends a certain amount of energy,
even at rest, to sustain vital functions of the body such
as brain activities, organ function, and temperature
regulation.
This energy requirement is called the basal metabolic
rate (BMR) and accounts for approximately 60 to 75
percent of the calories burned in 1 day. A true measure
of basal (resting) metabolism is taken when you have
been lying quietly but awake and without food for 12 to
15 hours. Most men have a BMR requirement of 1,600 to
2,000 calories daily; most women need 1,200 to 1,500
calories daily.
Factors That Affect Basal
Metabolic Rate
Your total daily caloric
expenditure is influenced by:
1. Basal Metabolism = 60 to 75
percent.
2. Digestion = 10 percent (e.g.,
if you consume 2,000 calories
a day, you burn 200 of them by
digesting the food).
3. Physical Activity and
Exercise = anywhere from 15
to 40 percent (you control
this!).
Remember, all physical activity
burns calories.
LIFETIME WEIGHT
MANAGEMENT: STRATEGIES
FOR SUCCESS
Maintaining a reasonable body
composition is, rather than isolated bouts
of crash dieting or sporadic exercise, a
result of lifelong integration of three
management components:
1. Food management
2. Emotional management
3. Exercise management
Food management
Emotional management
Eating behavior is strongly influenced
by psychological, social, and emotional
factors.
We eat out of emotional needs. We eat
when we're happy; we eat when we're
sad.
We confuse physical hunger with
emotional hunger
Emotional management
Controlling eating habits begins with
having an understanding of why you eat
and what cues trigger eating.
Food stops taking on the role of nurturer
when people learn to nurture themselves.
Emotional management works best when
you are reinforced by social support
family, friends, dietitians, community, and
weight-loss support groups.
Exercise Management
Exercise is crucial to losing weight and
maintaining weight.
In adults there is a direct relationship between
the number of hours spent watching television
and a person's level of obesity. The Internet,
computers, video games, and home movies
have decreased overall activity levels.
The secret to lifelong weight management is
exercise, not dieting.
While exercise is an important part of an initial
weight-loss program, it is the single best
predictor of long-term weight maintenance:
It Burns Calories
It Prevents Loss of Lean Muscle Mass
It Decreases Abdominal Fat
It Is a Natural Appetite Suppressor
It May Lower Your Set Point
It Helps Maintain Weight Loss
It Improves Self-Esteem
CULTURE AND WEIGHT
The desire for an unrealistic slimness, particularly among
women, has caused many to be preoccupied with their
bodies and with dieting. Diet books become instant bestsellers
This thin standard is perpetuated in all channels of social
influence: families, peers, and the media. The message
is pounded home over and over: "You can never be thin
enough."
Only about 5 percent of the population can look like the
models and actresses we are exposed to daily. Our
bodies are genetically programmed to be a certain buildtall, skinny, stout, short, muscular, big boned, and so on.
The dilemma of preventing obesity yet
avoiding a fostering of "thin mania" presents
a tremendous challenge.
Some of the general causes for eating disorders
include:
1. Society's definition of the "perfect body" as unrealistically thin and
lean.
2. Family characteristics such as over involvement and high
expectations; overvalue physical appearance; rigid and cold
emotionally.
3. Personality traits like "perfectionism," the desire to achieve;
feelings of inadequacy and loneliness.
General causes for eating
disorders :
4. A genetic propensity to being
overweight.
5. Pressure from others to lose weight,
including media images.
6. Appearance-obsessed friends (dance
troupes, school cliques, sororities,
cheerleaders).
7. An inherent presence of low selfesteem.
EATING DISORDERS
Bulimia Nervosa (criteria)
1. Recurrent episodes of binge eating (rapid
consumption of a large amount of food in a discrete
period).
2. A feeling of lack of control over eating behavior
during the eating binges.
3. Self-induced vomiting, misuse of laxatives or
diuretics, strict dieting or fasting, or excessive
exercise to prevent a weight gain.
4. Two binge episodes a week for at least 3 months.
5. Self-evaluation unduly influenced by body shape
and weight.
6. The bingeing and purging are not accompanied by
anorexia nervosa.
Anorexia Nervosa (criteria)
1. Refusal to maintain body weight at or above a
minimal normal level for age and height (i.e., a
body weight that is 15 percent below normal).
2. Intense fear of weight gain or becoming fat
despite being significantly underweight.
3. A disturbed perception of body weight, size, or
shape (i.e., feeling "fat" although emaciated).
4. In females, amenorrhea (lack of menstrual
periods) for at least three consecutive cycles.
Binge Eating Disorder
Binge eating disorder (BED) is defined as recurrent
episodes of eating characterized by eating, in a discrete
period, an amount of food much larger than most people
would eat in a similar period and accompanied by a
sense of lack of control or a feeling that one cannot stop.
At least three of the following must be part of the binge
episode:
1. Eating much more rapidly than normal.
2. Eating until uncomfortably full.
3. Eating large amounts of food when not hungry.
4. Eating alone because of embarrassment about how
much is eaten.
5. Feeling disgusted with oneself, depressed, or guilty
about eating.
Thank you for attention!