Over one-half of all Americans (about 97 million) are overweight or obese. If you are
overweight or obese, carrying this extra weight puts you at risk for developing many
diseases, especially heart disease, stroke, diabetes, and cancer. Losing this weight help to prevent and control these diseases.
Obesity is a condition of excess body fat. It is the most common form of malnutrition
in the Western world. It is important to note that no "diet or weight loss formula" works
independently of an eating plan based on the Dietary Guidelines given by the mainstream
nutrition and health institutes. So if you are obese throw away all those "special
formulas", supplements, and pills, stop eating more calories than you need, become more
physically active and adopt a healthy eating plan.
Severe overweight increases the risk for high blood cholesterol,
high blood pressure, and diabetes and, hence, for diseases for which
these conditions are risk factors (diabetes, coronary heart disease,
high blood pressure, neurologic disorders, cancers, and kidney
diseases). Obesity thus contributes to premature mortality. Of all
obesity-related diseases, noninsulin dependent diabetes is most clearly
and strongly associated with obesity.
Obesity is associated with too many adipose cells (hyperplastic obesity), adipose cells
that are too large (hypertrophic obesity), or both. While changes in the size of adipose
cells may occur at any age, the number of adult cells are fixed and determined by weight
gain during certain periods of childhood development; fat cell numbers are established by
late adolescence and, once established, does not decline.
Women generally have more subcutaneous fat than men, but men appear
to suffer a greater cardiovascular risk from a given degree of fat than
women. The distribution of body fat may be an indicator of this
difference. Men accumulate more fat cells in the abdominal region than
women (high waist-to-hip ratio). This distribution around the abdomen,
referred to as upper body obesity, is associated with increased
cardiovascular risk factors. Lower body obesity is more typical in
women, who tend to accumulate fat in the hips, gluteal regions, and
extremities, a distribution that does not appear to be associated with
increased cardiovascular risk factors.
Regardless of gender, a high waist-to-hip ratio predicts an increased risk for
cardiovascular disease and diabetes. The mortality ratio has been shown to increase
with the degree of obesity, and with its duration.
Obesity is the net result of an excess of energy consumption over expenditure. Factors
that must be considered as contributing to causation are: heredity, overeating, altered
metabolism of adipose tissue, defective or decreased thermogenesis (the process by which
calories are converted to heat), decreased physical activity without an appropriate
reduction in food intake, and certain prescribed medications.
Overeating is clearly a prominent contributor to obesity. Feeding
behaviour occurs in response to hunger and to appetite inducedby the
presence of food. Satiety and the resulting cessation of eating occur
in response to certain hormones, nervous impulses, and absorbed
nutrients signalling the brain.
To loose weight, one must decrease caloric intake, increase caloric expenditure, or do
both. Thus, the chief approaches to weight reduction involve behaviour change related to
diet and exercise. Weight loss reduces health risks in the obese. Because obesity is a
condition requiring continuous attention, any behaviour changes required to maintain
weight loss must be life long.
With so many complex mechanisms causing a person to eat more than is needed, it is
acceptably difficult to follow a strict recommended weight-loss program.
Key Recommendations
(From the Expert Panel on the Identification, Evaluation, and Treatment of Overweight
and Obesity in Adults)
- Weight loss to lower elevated blood pressure in overweight and obese persons with
high blood pressure. - Weight loss to lower elevated levels of total cholesterol, LDL-cholesterol, and
triglycerides, and to raise low levels of HDL-cholesterol in overweight and obese persons
with dyslipidemia. - Weight loss to lower elevated blood glucose levels in overweight and obese persons
with type 2 diabetes. - Use the BMI to assess overweight and obesity. Body weight alone can be used to
follow weight loss, and to determine the effectiveness of therapy. - The BMI to classify overweight and obesity and to estimate relative risk of disease
compared to normal weight. - The waist circumference should be used to assess abdominal fat content.
- The initial goal of weight loss therapy should be to reduce body weight by about 10
percent from baseline.
With success, and if warranted, further weight loss can be attempted. - Weight loss should be about 1 to 2 pounds per week for a period of 6 months, with
the subsequent strategy based on the amount of weight lost. - Low calorie diets (LCD) for weight loss in overweight and obese persons. Reducing
fat as part of an LCD is a practical way to reduce calories. - Reducing dietary fat alone without reducing calories is not sufficient for weight
loss. However, reducing dietary fat, along with reducing dietary carbohydrates, can help
reduce calories. - A diet that is individually planned to help create a deficit of 500 to 1,000
kcal/day should be an intregal part of any program aimed at achieving a weight loss of 1
to 2 pounds per week. - Physical
activity should be part of a comprehensive weight loss therapy and
weight control program because it: (1) modestly contributes to weight
loss in overweight and obese adults, (2) may decrease abdominal fat,
(3) increases cardiorespiratory fitness, and (4) may help with
maintenance of weight loss. - Physical
activity should be an integral part of weight loss therapy and weight
maintenance. Initially, moderate levels of physical activity for 30 to
45 minutes, 3 to 5 days a week, should be encouraged. All adults should
set a long-term goal to accumulate at least 30 minutes or more of
moderate-intensity physical activity on most, and preferably all, days
of the week. - The combination of a reduced calorie diet and increased physical activity is
recommended since it produces weight loss that may also result in decreases in abdominal
fat and increases in cardiorespiratory fitness. - Behavior therapy is a useful adjunct when incorporated into treatment for weight
loss and weight maintenance. - Weight loss and weight maintenance therapy should employ the combination of LCD's,
increased physical activity, and behavior therapy. - After
successful weight loss, the likelihood of weight loss maintenance is
enhanced by a program consisting of dietary therapy, physical activity,
and behavior therapy which should be continued indefinitely. Drug
therapy can also be used. However, drug safety and efficacy beyond 1
year of total treatment have not been established. - A weight maintenance program should be a priority after the initial 6 months of
weight loss therapy.
Some people lose weight on their own; others like the support of a structured program.
Overweight people who are successful at losing weight, and keeping it off, can reduce
their risk factors for heart disease. If you decide to join any kind of weight control
program, here are some questions to ask before you join.
Does the program provide counseling to help you change your eating
activity, and personal habits? The program should teach you how to
change permanently those eating habits and lifestyle factors, such as
lack of physical activity that have contributed to weight gain.
Is the staff made up of a variety of qualified counselors and health professionals such
as nutritionists, registered dietitians, doctors, nurses, psychologists, and exercise
physiologists?
Is training available on how to deal with times when you may feel stressed and slip
back to old habits?
Is attention paid to keeping the weight off? How long is this phase?
Choose a program that teaches skills and techniques to make permanent changes in eating
habits and levels of physical activity to prevent weight gain.
Are food choices flexible and suitable? Are weight goals set by the client and the
health professional?
The program should consider your food likes and dislikes and your lifestyle when your
weight loss goals are planned.
