INTRODUCTION
CONCLUSION
REFERENCES
 

OBESITY: AN OVERVIEW
Salma Nikhat, MBBS

From the Joint Centre for Research in Prosthetics & Orthotics and Rehabilitation Programmes (JCRPO), Kingdom of Saudi Arabia. Address reprint requests to: Prof. Mohammed H. S. Al-Turaiki, Principal Investigator & Director General, JCRPO, P.O. Box 27240, Riyadh 11417, Kingdom of Saudi Arabia, Tel: +966 (1) 4970399/4938006, Fax: +966 (1) 4931281

Obesity is probably one of the oldest metabolic disorders. It is defined as excessive accumulation of body fat¹. People in a society become obese as soon as enough food and leisure are available to cause an imbalance between energy intake and energy expenditure. Forty million adult Americans weigh more than 20% above their desirable weight. Its prevalence is increasing in all major race/sex groups including younger adults aged 25 to 44. It is also assuming a significant proportion in the developing countries². Obesity is, therefore, becoming a more important risk factor for the development of diabetes, hypertension and cardiovascular disease. A man is considered obese when his weight is 20% or more over the maximum desirable weight for his height and a woman is obese when her weight is 25% or more over the maximum desirable weight for her height. In children it is 72.5% in boys and 73.2% fat in girls is considered obesity³. Men 20% above desirable weight show an overall increase of 20% in the likelihood of death from all causes, a 25% increase in death from coronary artery disease, a 10% increase from stroke, twice the risk of diabetes, and a 40% increase in gall bladder disease. Gallbladder pathology and endometrial cancer are more common among obese females. In general, the life expectancy is shorter. A less well known complication of obesity among females is infertility. Overweight adolescents have a 70% chance of becoming overweight or obese adults. This increases to 80% if one or more parent is overweight or obese.
The clinical approach to the management of obesity can be similar to the management of other chronic disorders such as diabetes, hyperlipidemia or most forms of hypertension. Lifelong dietary therapy and possibly long-term pharmacological or behavioural treatment would be required to control obesity successfully. Given the high rate of recidivism following weight reduction, weight reduction targets should be realistic, and modest weight loss or maintenance of a steady body weight may be appropriate therapeutic goals. The treatment of obesity should be individualized depending on each patient's age, BMI (Body Mass Index), and the coexistence of other diseases such as diabetes, hypertension or hyperlipidemia which have been linked to obesity.
This article presents an overview of obesity including: etiology, prevalence, indices of measurement, health implications and prevention.

Key Words: Obesity, Overweight, Mortality, Risk, Death

INTRODUCTION :
          Adipose tissue is a normal constituent of the human body that serves the important function of storing energy as fat for mobilization in response to metabolic demands. Obesity is an excess of body fat frequently resulting in a significant impairment of health. The excess fat accumulation is associated with increased fat cell size; in individuals with extreme obesity, fat cell numbers are also increased. Although the etiologic mechanisms underlying obesity require further clarification, the net effect of such mechanisms leads to an imbalance between energy intake and expenditure. Both genetic and environmental factors are likely to be involved in the pathogenesis of obesity. These include excess caloric intake, decreased physical activity, and metabolic and endocrine abnormalities. Hence, a number of subtypes of obesity exist⁴.
          The major health risks of obesity increase in a curvilinear relationship, with prevalences increasing progressively and disproportionately with increasing weight. Most adverse effects are due to the weight gain acquired during adulthood, which continues thereafter.
          The body cannot store protein or carbohydrates, so excess protein or carbohydrate intake is converted to fat and stored. One Pound of fat represents about 3,500 excess calories.
          More than half of the U.S. population is overweight. But being obese is different from being overweight. An individual is considered obese when weight is 20% (25% in women) or more over the maximum desirable for his/her height. When an adult is more than 100 pounds overweight, it is considered morbid obesity.

1.       Prevalence of Obesity
1.1     In Saudi Arabia
          The prevalence of obesity in the 15-70 year age group is 13.05% and 20.26% in the Saudi males and females⁵. However, the Saudi females in the age group 15- 70 years appear to have the maximum prevalence of obesity. The prevalence of overweight and obesity are alarmingly high among infertile Saudi females.

1.2     In United States of America
          Rates of obesity are climbing and have risen from 12 to 20 percent of the population since 1991⁶. An ominous 

statistic which indicates that the epidemic of obesity may get even worse is that the percentage of children and adolescents who are obese has doubled in the last 20 years. The prevalence of overweight and obesity increases until about age 60, after which it begins to decline. In women, overweight and obesity are higher among members of racial and ethnic minority populations than in non-Hispanic white women. 61% of adults in the United States were overweight or obese (BMI > 25) in 1999. 300,000 deaths each year in the United States are associated with obesity.

1.3     In Children
          Between 5-25 percent of children and teenagers in the United States are obese⁷. As with adults, the prevalence of obesity in the young varies by ethnic group. It is estimated that 5-7 percent of White and Black children are obese, while 12 percent of Hispanic boys and 19 percent of Hispanic girls are obese⁸.

1.4     In Women
Coronary heart disease is every woman's concern. One in ten American women 45 to 64 years of age have some form of heart disease, and this increases to one in four women over 65. Another 1.6 million women have had a stroke19. Both heart disease and stroke are known as cardiovascular diseases, which are serious disorders of the heart and blood vessel system.

2.       Etiology of Obesity
2.1     In Adults
          The etiology of obesity is complex and multifactorial and both genetic and environmental factors play an important role in its development. It tends to concentrate in families, though no specific pattern of inheritance has been observed.
          The complex interactions of psychosocial and cultural factors that create susceptibility to human obesity indicate that this disease in man is complex and deeply rooted in biological systems. Thus, it is almost certain that obesity has multiple causes and that there are different types of obesity⁹.
          Overweight and obesity are caused by many factors. These factors reflect the contributions of inherited, metabolic, behavioral, environmental, cultural, and socioeconomic components. As weight increases, so does the prevalence of health risks. Simple, health-oriented definitions of overweight and obesity should be based on the amount of excess body fat at which health risks to individuals begin to increase. No such definitions currently exist. Most current clinical studies assessing the health effects of overweight rely on a measurement of body weight adjusted for height. BMI (Body Mass Index) is the choice for many researchers and health professionals. While the relation of BMI to body fat differs by age and gender, it provides valid comparisons across racial and ethnic groups¹⁰.
          For each individual, body weight is the result of a combination of genetic, metabolic, behavioral, environmental, cultural, and socioeconomic influences. Behavioral and environmental factors are large contributors to overweight and obesity and provide the greatest opportunity for actions and interventions designed for prevention and treatment.

2.2       In Children
          As with adult-onset obesity, childhood obesity has multiple causes centering around an imbalance between energy-in (calories obtained from food) and energy-out (calories expended in the basal metabolic rate and physical activity). Childhood obesity most likely results from an interaction of nutritional, psychological, familial, and physiological factors.

• The Family: The risk of becoming obese is greatest among children who have two obese parents. This may be due to powerful genetic factors or to parental modeling of both eating and exercise behaviors, indirectly affecting the child's energy balance. One half of parents of elementary school children never exercise vigorously.

• Low-energy Expenditure: Obesity is greater among children and adolescents who frequently watch television, not only because little energy is expended while viewing but also because of concurrent consumption of high-calorie snacks. Only about one-third of elementary children have daily physical education, and fewer than one-fifth have extracurricular physical activity programs at their schools.

• Heredity: Since not all children who eat non-nutritious foods, watch several hours of television daily, and are relatively inactive develop obesity, the search continues for alternative causes. Heredity has recently been shown to influence fatness, regional fat distribution, and response to overfeeding¹¹. In addition, infants born to overweight mothers have been found to be less active and to gain more weight by age three months when compared with infants of normal weight mothers, suggesting a possible inborn drive to conserve energy.

• Our society has become very sedentary. Television, computer and video games contribute to children's inactive lifestyles. 43% of adolescents watch more than 2 hours of television each day. Children, especially girls, become less active as they move through adolescence.

3.       Indices for Measurement of Fat
          The precise determination of the amount of body fat requires technically sophisticated methods that are available only in research laboratories. For public health studies and clinical practice, simple and convenient anthropometric measurements based on height, weight, and skinfold thickness are recommended. For adults of 20 years and older, two methods are now in wide use: (1) estimation of relative weight (RW = measured body weight divided by midpoint of medium frame desirable weight recommended in the 1959 or 1983 Metropolitan Life Insurance Company tables) and (2) calculation of body mass index (BMI = [body weight in kg] divided by [height in m²]). Because body composition varies among individuals of the same height and weight, these measurements only approximate the precise magnitude of fatness¹⁰. Nevertheless, they correlate with the risk of adverse effects on health and longevity. Separate criteria must be used for evaluating fatness in children and adolescents.
                                         Body wt in Kg
                            BMI = -----------------
                                            (Ht in m)²

          Adipose tissue depots do not constitute a uniform organ; fat cells around the waist and flank and in the abdomen are more active metabolically than those in the thigh and buttocks. The location of body fat has emerged as an important predictor of the health hazards of obesity. Sites of body fat predominance are easily measured by the ratio of waist to hip circumferences. High ratios are associated with higher risks for death and illness.
          Based on indices of body fat, studies of large popu-lations have shown that there is a continuous relationship between RW or BMI and morbidity and mortality. Thus, it becomes important to establish ranges of these indices as guidelines for developing appropriate and effective approaches for the treatment and prevention of obesity.
          Since the amount of body fat, as estimated by the above indices, is a continuous variable within the population, all quantitative definitions of obesity must be arbitrary. There is a general agreement that an increase in body weight of 20 percent or more above desirable body weight constitutes an established health hazard. Significant health risks at lower levels of obesity can present hazards, especially in the presence of diabetes, hypertension, heart disease, or their associated risk factors.
          To determine whether an individual is obese or simply overweight because of increased muscle mass, one needs techniques for quantitating body fat.
          Skinfold measurements can also be used to measure body fat¹². They are easy to do, inexpensive, and portable; if one measures appropriate skinfolds, an equation may be used to estimate body fat. Approximately half the fat in the body is deposited in the skin. The percentage of internal fat increases with increasing weight. Skinfold measurements are often not accurate or reproducible, especially if the observer is inexperienced. Skinfolds are not equally compressible and skin thickness is not necessarily constant.
          More precise and technically sophisticated methods for determining body fat include underwater weighing, which requires total submersion of an individual and an accurate estimation of lung and abdominal gas, the assessment of total body water by dilution of tritiated water, and measurement of body fat by dilution of an inert fat-soluble gas such as Xenon. CT, ultrasound, and MRI have also been used to determine body fat. These measures are all expensive, difficult to do, time consuming and not applicable to office practice.
          Bioelectrical impedance analysis appears to be the first easy-to-use, reproducible method for determining body composition in office practice. Body impedance is measured when a small amount of current, applied through electrodes, flows through the body. Resistance is inversely proportional to total body water through which the current travels. Lean body mass and body fat are derived from total body water. Impedance measurements correlate quite well with total body water measured by other means.
          There is consensus that a measure of obesity is needed to overcome the subjectivity introduced by simply relying on visual inspection as an estimate of obesity. Equipment for measuring height and weight, height-weight tables, and weight-related indices are widely available¹³.

4.       Health Implications of Obesity
          Obesity will increase the risk of illness and death due to diabetes, stroke, coronary artery disease, hypertension, high cholesterol, and kidney and gall bladder disorders. Obesity has been implicated in increased risk for some types of cancer. It is also a risk factor for the development of osteoarthritis and sleep apnea¹⁴.
          Overweight and obesity are associated with increased risks of gall bladder disease, incontinence, increased surgical risk, and depression. Obesity can affect the quality of life through limited mobility and decreased physical endurance as well as through social, academic, and job discrimination.
          Risk factors for heart disease, such as high cholesterol and high blood pressure, occur with increased frequency in overweight children and adolescents compared to those with a healthy weight. Type 2 diabetes, previously considered an adult disease, has increased dramatically in children and adolescents. Overweight and obesity are closely linked to type 2 diabetes. Overweight adolescents have a 70% chance of becoming overweight or obese adults. This increases to 80% if one or more parent is overweight or obese. The most immediate consequence of overweight, as perceived by children themselves, is social discrimination.

4.1     Obesity and Hypertension
          Hypertension is a common concomitant of obesity. In overweight young adults, age 20-45, the prevalence of hypertension is 6 times that of their normal-weight peers. Weight gain in young adult life is a potent risk factor for the later development of hypertension¹⁵.
          The distribution of fat in the body may have an important effect on blood pressure risk, with central or upper body fat being more likely to raise blood pressure than lower body fat in the gluteal or thigh region. In obese patients, an accumulation of abdominal fat results in the release of free fatty acids into the portal vein which causes an excess hepatic synthesis of triglycerides, insulin resistance and hyperinsulinemia.

4.2    Obesity and Diabetes
          Even moderate obesity, particularly abdominal obesity, can increase the risk of non-insulin dependent diabetes mellitus (NIDDM) ten-fold. Fat tissue apparently has two roles in promoting diabetes: it increases the demand for insulin and, in obese individuals, it creates insulin resistance, and, therefore, hyperinsulinemia¹⁶. Adipose tissue sensitivity to insulin remains high. It is therefore possible that nutrients are preferably sent into fat for storage.
          Some of the insulin resistance in obesity can be attributed to a decrease in insulin receptors; there are also intracellular post-receptor defects. Weight reduction in the obese NIDDM will lead to improvement of glycemic control as well as improvement of concomitant medical problems such as hypertension or hyperlipidemia.

4.3     Cardiovascular Disease and Fat Distribution
          In long duration studies, such as the Framingham Study, an increased risk of cardiovascular disease is noted with increasing levels of obesity independent of other risk factors. It is calculated that, in men, for each 10% increase in body weight there is approximately a 20% increase in the incidence of coronary artery disease. For every 10% increase in relative body weight, systolic blood pressure increases 6.5 mm/Hg, plasma cholesterol 12 mg/dL and fasting blood glucose 2 mg/dL.
          Acquired obesity in men tends to be localized to the trunk. Both the degree of obesity and the distribution of body fat, independently and additively, contribute to the risk factors for cardiovascular disease. The simplest way to measure the degree of abdominal obesity is to record the waist circumference and divide it by the hip circumference. In men, the risk of cardiovascular disease increases sharply when waist/hip ratio (WHR) is above 1.0, and in women above 0.8. Numerous reports have indicated that a high proportion of either truncal or abdominal fat is associated with insulin resistance, hyperinsulinemia, impaired glucose tolerance, diabetes, an athrogenic plasma lipid profile and an elevated blood pressure. It has been postulated that high levels of total body fat must be present to observe the deleterious effects of visceral fat on plasma lipoprotein metabolism¹⁷. Human adipose cells specifically bind HDL. This binding is related to fat cell size. In patients with abdominal obesity, there may be a disproportionate uptake of HDL cholesterol contributing to the reduction in plasma levels.
          The abdominal visceral fat depot primarily functions for storage of easily and rapidly mobilizable energy reserves. In women the femoral-guteal depot functions primarily as a storage organ dedicated to female stresses such as pregnancy and lactation.
          This anatomical and functional specialization is governed by sex hormone balance. In premenopausal obese women, as the waist/hip ratio increases, there is a progressive decrease in sex hormone binding globulin and an increase in free testosterone levels. Increased androgenic activity also increases plasma free fatty acid levels and contributes to abnormalities in insulin dynamics. It has been suggested that the abdominal fat pattern may represent an increase in the size and the number of metabolically active intra-abdominal fat cells. Hypertrophy of the abdominal adipocytes in the upper-body obese might also be a manifestation of hyperandrogenicity. These fat cells release fatty acids directly into the portal circulation and might interfere with insulin clearance in the liver and thus affect various metabolic processes.
          The association of abdominal fat with metabolic abnormalities is additive to the effects of generalized body obesity. Even mild to moderate obesity should be treated if excess adipose tissue is found mainly in the abdominal region. To assess cardiovascular risk, it is recommended that the WHR be used simultaneously with the determination of total body fat.

4.4     Obesity and Cancer
          Overweight men have a significantly higher mortality rate for colorectal and prostate cancer; men whose weight is 130% or more above average are 2.5 times more likely to die of prostate cancer during a 20 year follow-up compared to men of average weight¹⁸. Menopausal women with upper body fat localization have an increased risk of developing breast cancer. Overweight women also have higher rates of cancer of the uterus and ovaries. Obesity is also correlated with increased estrogenicity of cervical smears. These problems may reflect an increase in the conversion of estrogen to androgens by the stromal elements of adipose tissue.

4.5     Obesity and Endocrine Abnormalities
          Obese women, especially those with upper body obesity, show more irregularity in menstrual cycles as well as greater frequency of other menstrual abnormalities than normal weight women. They also have more problems during pregnancy with an increased frequency of toxemia and hypertension. In obese girls, the onset of menarche occurs at a younger age than in normal weight girls. Menstruation is probably initiated when body weight reaches a critical mass.

4.6     Obesity and Gall Bladder
          Obese women in the 20-30 year age range have a six-fold increase in the risk of developing gall bladder disease compared to normal-weight women. By age 60, nearly one-third of obese women can be expected to have developed gall bladder disease.
          For each kilogram of fat, approximately 20 mg/dL of cholesterol is synthesized. In obese persons, the bile is therefore more saturated with cholesterol. There is also hypermotility of the gall bladder. Fatty infiltration of the liver, stasis, is associated with obesity. However, this abnormality is generally not associated with abnormal liver function tests.

4.7     Reproductive Complications
          Obesity during pregnancy is associated with increased risk of death in both the baby and the mother and increases the risk of maternal high blood pressure by 10 times. In addition to many other complications, women who are obese during pregnancy are more likely to have gestational diabetes and problems with labor and delivery. Infants born to women who are obese during pregnancy are more likely to be high birthweight and, therefore, may face a higher rate of Cesarean section delivery and low blood sugar (which can be associated with brain damage and seizures). Obesity during pregnancy is associated with an increased risk of birth defects, particularly neural tube defects, such as spina bifida. Obesity in premenopausal women is associated with irregular menstrual cycles and infertility¹⁹.

5.       Treatment of Obesity in Adults
          After five to ten years of intervention there was no significant difference in the average weight loss in the communities which received education as compared to control communities. Other educational interventions aimed at reducing cardiovascular risk factor prevalence have met with similarly disappointing results²⁰.

5.1     Behavioral Therapy
          Behavioral therapy when used alone for the treatment of obesity will lead to only modest weight loss (i.e. 0.5-0.75 kg/week). Consequently, this form of treatment is usually used in concert with other weight reduction methods. It has been postulated that long-term behavioural therapy may reinforce the necessary lifestyle and cognitive changes required to maintain long-term weight loss.

5.2     Fasting used as a Therapy
          Fasting is a discipline that spans religion and politics. For centuries, believers of many faiths have periodically shunned food to exercise self-discipline and heighten their spiritual awareness. One-day fasts pose no serious threat for healthy adults. However, longer fasts involve a serious health threat, this does not mean the Ramadan fasts, since those are for limited time and are beneficial.
          The following persons should not fast at all: children; teenagers; pregnant and nursing women; persons with heart disease, insulin-dependent diabetes, kidney or liver problems.

A crisis for your body
          Fasting is a drastic challenge to your system. The only difference between fasting and starvation is that fasting is a matter of choice - but your body does not know that. It reacts by going into a state of emergency.
          Your body must draw on its reserves to provide energy because an inadequate amount of food is being supplied. The body first turns to glucose from the liver's stores of glycogen. This supply lasts less than one day. After that, the body must turn to muscle tissue to supply protein and other substances it can make into glucose. If fasting is prolonged, muscles throughout the body, including those in vital organs such as the heart, diminish in size because their protein is being depleted by the body.
          If you fast longer than 24 hours, your body tries to protect itself by producing another energy source called ketones. Ketones are made from fat. As the amount of ketones in your bloodstream increases, your body reacts by trying to eliminate them. This can cause dehydration and loss of electrolytes. Electrolytes are substances such as sodium, chloride and potassium that are necessary for transmitting nerve impulses, making muscles contract and maintaining a proper level of fluid in and around body cells. Dizziness, dry skin, blood pressure irregularities, increased urination and heart irregularities are potential side effects associated with dehydration and loss of electrolytes.
          You will lose weight, of course, but much of it will be water. Only about one-fourth of a pound of fat is lost each day of the continued fast. And the longer you fast, the less effective your weight loss. To prevent death by starvation, the body slows its metabolism, using as few calories as possible.

When you end a fast
          Weight gain is common when you break a fast. When you begin to eat again, your body retains fluids and this alone can return 5 to 7 pounds to your frame. Also, your slowed metabolism means it takes less food than before to put on pounds.
          Fasting is not the answer to permanent weight loss. There will come a time when, once again, you confront choices at the table. Learn the healthful ways to select and prepare food so that weight management becomes a way of life.

5.3     Diet Therapy
          The first approach to treat obesity is and must remain diet²¹.

Balanced low-calorie diet
          Each individual is unique. The history, family and medical background, the way of life and tastes vary from one person to the next. It is important that the dietician have a personalized program that takes into account these elements for a person wanting to lose weight. Food intake must be reviewed and food modified. Simples rules enable significant weight-loss, provided food supply is healthy, varied and balance, providing all the essential nutrients (proteins, lipids, glucides), vitamins, minerals, fatty-acids and fibres.

The Food Guide Pyramid
          The Food Guide Pyramid is an outline of what to eat each day based on the Dietary Guidelines. It's not a rigid prescription but a general guide that lets you choose a healthful diet that's right for you²³.
Start with plenty of breads, cereals, rice, pasta, vegetables, and fruits. Add 2-3 servings from the mild group and 2-3 servings from the meat group. Remember to go easy on fats, oils, and sweets, the foods in the small tip of the Pyramid.

The Top of the Pyramid
          Fats, oils and sweets should be used sparingly in the diet and therefore are represented as the small tip of the pyramid. This includes salad dressings, oils, cream, butter, margarine, soft drinks, candies, and sweet desserts. These foods provide calories but little or no vitamins and minerals.

The Middle of the Pyramid
          Protein is needed in moderate amounts in the diet and therefore represents the upper middle of the pyramid. Milk, yogurt, cheese; and meat, poultry, fish, dry beans, eggs and nuts - two groups of foods that come mostly

from animals - are important for protein, calcium, iron and zinc. Choose lean meats, skinless poultry, fish and low-fat dairy products to control fat and cholesterol. Also, limit breaded or fried foods to control fat and calories. Many people need to eat more fruits and vegetables which help form the foundation of the pyramid. Besides being an excellent source of vitamins, minerals and fiber, vegetables and fruits (plant foods) are low-fat, low-sodium and cholesterol-free. Eating a variety of vegetables and fruits will help ensure that you meet your daily need for Vitamin C and other nutrients.

The Base of the Pyramid
          Bread, cereals, rice and pasta - all foods from grains - are found at the base of the Pyramid because they are the foundation uponwhich the rest of the diet is planned. Try to choose 6-11 servings daily. Grains supply fiber, carbohydrates, vitamins and minerals. They are usually low in fat and are the preferred fuel for our brain, nervous system and muscles. To keep these foods low in fat and calories, limit the use of spreads.

What Counts as One Serving?
          The amount of food that counts as one serving is listed below. If you eat a larger portion, count it as more than 1 serving. For example, a dinner portion of spaghetti would count as 2 or 3 servings of pasta.
          Be sure to eat at least the lowest number of servings from the five major food groups listed below. You need

them for the vitamins, minerals, carbohydrates, and protein they provide. Just try to pick the lowest fat choices from the food groups. No specific serving size is given for the fats, oils, and sweets group because the message is USE SPARINGLY.

Limit portion size
          Eat smaller portion Ð do not go back for seconds.
          Try eating only one serving of high-fat, high-calorie foods like pizza, ice cream, or chips. Slowly cut back on your portion size. Substitute with lower fat, lower calorie foods during the rest of the day

Choose lower fat, lower calorie foods

• Prepare food by broiling or baking more often instead of frying.

• Eat fewer breaded and fried foods. Breading and frying foods like fish, shrimp, chicken, and vegetables add fat and calories.

• Eat lean meat, fish, and poultry without skin. Choose poultry breasts and drumsticks more often than the wings and thighs.

• Eat more fruits, whole grain, and vegetables. If you are a nibbler, choose fruit and vegetables as snacks more often.

• Use the food label to choose lower calorie foods.

• Drink fewer alcoholic and high-calorie beverages.

• Drink six to eight glasses of water each day.

How much should you eat?
          1200 calories is the lowest amount recommended to maintain nutritional adequacy; this calorie level is con-ducive for weight loss, or extremely inactive individuals.
          1600 calories is recommended for many sedentary women and some older adults.
          2200 calories is recommended for most children, teenage girls, active women and sedentary men; women who are pregnant or breastfeeding may need more.
          2500 calories is recommended for teenage boys, active men, and some very active women.

Long-term goal to maintain a healthy weight

• Choose lower fat, lower calorie foods more often.

• Eat more slowly.

• Eat more fruits and vegetables for snacks.

• Use the stairs instead of the elevator.

• Drink water instead of soft drinks with sugar.

• Use less high-fat cheeses, cream, shortening, and butter when cooking.

5.4     Exercise Therapy
          Regular physical activity of exercise can help to reduce the risk of coronary heart disease. Being active helps women take off extra pounds, helps to control blood pressure, lessens a diabetic's need for insulin, and boosts the level of "good" HDL-cholesterol. Some studies also show that being inactive increases the risk of heart attack.
          Even low- to moderate-intensity activity can help lower the risk of heart disease. Examples of such activity are pleasure walking, stair climbing, gardening, yardwork, moderate-to-heavy housework, dancing, and home exercise. To get heart benefits from these activities, do one or more of them every day²⁴.
          More vigorous exercise improves the fitness of the heart, which can lower heart disease risk still more. This kind of activity is called "aerobic" and includes jogging, swimming, and jumping rope. Walking, bicycling, and dancing can also strengthen your heart, if you do them briskly for at least 30 minutes, three or four times a week.
         Most people do not need to see a doctor before they start a gradual, sensible program of physical activity. But do consult your doctor before you start or increase physical activity if you:

• have heart trouble or have had a heart attack

• are taking medicine for high blood pressure or a heart condition

• are over 50 years old and are not used to energetic activity

• have a family history of developing heart disease at a young age

The Keys to Success
          Go slow. Build up your activity level gradually. For example, if you are inactive now and want to begin walking regularly, you might begin slowly with a 10-15-minute walk, three times a week. As you become more fit, you can increase the sessions to every day, and if you wish, you can make each session longer.
          If you choose a fairly vigorous activity, begin each session slowly. Allow a 5-minute period of stretching and slow movement to give your body a chance to "warm up". At the end of your workout, take another 5 minutes to "cool down" with a slower exercise pace.
          Listen to your body. A certain amount of stiffness is normal at first. But if you hurt a joint or pull a muscle or tendon, stop the activity for several days to avoid more serious injury. Most minor muscle and joint problems can be relieved by rest and over-the-counter pain-killers.
          Pay attention to warning signals. While regular physical activity can strengthen your heart, some types of activity may worsen existing heart problems. Warning signals include sudden dizziness, cold sweat, paleness, fainting, or pain or pressure in your upper body just after exercising. If you notice any of these signs, stop the activity and call your doctor immediately.
          Unless you have to stop your regular physical activity for a health reason, stay with it. Set small, short-term goals for yourself. If you find yourself becoming bored, try doing the activity with a friend or family member. Or switch to another activity. The health rewards of regular physical activity are well worth the effort.

Making Opportunities
          To become more physically active throughout your day, take advantage of any opportunity to get up and move around. For example:

• Use the stairs--up and down--instead of the elevator. Start with one flight of stairs and gradually build up to more.

• Park a few blocks from the office or store and walk the rest of the way. Or if you ride on public transportation, get off a stop or two early and walk a few blocks.

• Instead of eating that extra snack, take a brisk stroll around the neighborhood.

• Do housework, such as vacuuming, at a brisker pace.

• Mow your own lawn.

• Carry your own groceries.

• Take an exercise break--get up and stretch, walk around and give your muscles and mind a chance to relax.

 

Calories burnt per hour in common activities25

The Benefits of Regular Physical Activity
          Regular activity can help you feel better because it:

• Boosts energy

• Helps you cope with stress

• Improves self-image

• Increases resistance to fatigue

• Helps counter anxiety and depression

• Helps you relax and feel less tense

• Improves your ability to fall asleep and sleep well

• Provides an easy way to share time with friends or family and an opportunity to meet new friends

• Regular activity can help you look better because it:

• Tones muscles

• Burns off calories to help lose extra pounds or to help you stay at your desirable weight-each pound requires you to burn off 3,500 more calories than you take in

• Helps control your appetite

Balance your food intake and your activity

• One small chocolate chip cookie (50 calories) is equivalent to walking briskly for 10 minutes.

• The difference between a large gourment chocolate chip cookie and a small chocolate chip cookie could be about 40 minutes of raking leaves (200 calories).

• One hour of walking at a moderate pace (20 min/mile) uses about the same amount of energy that is in one jelly filled doughnut (300 calories).

• A fast food "meal" containing a double patty cheeseburger, extra-large fries and a 24 oz. Soft drink is equal to running 21/2 hours at a 10 min/mile pace (1500 calories)²⁶.

5.5     Medical Management of Obesity
          Many different agents are available for the medical management of obesity²⁷.
          Two classes of anorectic drugs are currently available in the U.S.: noradrenergic agents and serotonergic agents. Within the noradrenergic class, diethylpropion (Tenuate), mazindol (Sanorex), phenylpropanolamine (Dexatrim), phentermine (Fastin) and phendimetrazine (Bontril) are characteristic medications. These medications preserve the anorectic effects of amphetamines with weaker stimulant activity and little abuse potential.
          All of the noradrenergic drugs except phenylpropanolamine act through a centrally mediated pathway in the hypothalamus that causes anorexia²⁸. Phenylpropanolamine, a racemic mixture of norephedrine esters, causes a release of norepinephrine throughout the body and stimulates hypothalamic adrenoreceptors to reduce appetite.
          Side effects for this class of drugs include insomnia, nervousness, irritability, headache, nausea and constipation. Mazindol and phentermine have the potential to increase blood pressure and precipitate angina in some persons and should be used with caution in patients with cardiac risk factors. Phenylpropanolamine is believed by some to cause an elevation in blood pressure, although others disagree. Diethylpropion is thought to have a more tolerable side effect profile. Abuse potential is extremely low for these agents.
          Serotonergic agents include fenfluramine (Pondimin) and dexfenfluramine (Redux). Fenfluramine and dexfenfluramine stimulate release of serotonin and inhibit its reuptake. They have been shown to cause weight loss in obese persons²⁹. These medications were withdrawn from the market after valvular heart disease was reported in a small number of patients using the combination of fenfluramine and phentermine.
          Sibutramine (Meridia) is a novel agent that inhibits the reuptake of serotonin, norepinephrine and dopamine. It does not stimulate secretion of serotonin. The drug produces weight loss by its anorectic effect.
          In one study of patients with type 2 diabetes³⁰, sibutramine produced significant weight loss compared with placebo, but less weight loss than in nondiabetic patients. Interestingly, the treated group also experienced a decrease in glycosylated hemoglobin levels, although it is not known whether this loss was related directly to sibutramine or was a result of the patients overall weight loss. Other studies have shown that sibutramine can reduce hyperinsulinemia and increase insulin-mediated glucose disposal, resulting in decreased insulin resistance³¹. Whether this effect is caused by sibutramine directly or is a result of reduced adiposity in the subjects is unclear.
          Adverse effects attributed to sibutramine include headache, insomnia, constipation and dry mouth. Increases in blood pressure (mean 2 mm Hg in both systolic and diastolic blood pressure) and pulse rate (3 to 6 beats per minute) may also occur. Patients with cardiac conditions should be given this drug with caution. The manufacturer advises against giving sibutramine to patients with a history of coronary artery disease, congestive heart failure, arrhythmias or stroke.
          Orlistat (Xenical) is a weight loss medication of novel mechanism. A lipase inhibitor, it acts in the gastrointestinal tract to decrease fat absorption. The drug is not absorbed but instead inhibits pancreatic and gastric lipases, thus reducing triglyceride hydrolysis. Unabsorbed triglycerides and cholesterol are excreted in feces. Studies have shown weight loss of 8.5 percent at one year compared with 5.4 percent for placebo.
          Patients lost an average of 8.8 kg in the first year, compared with 5.8 kg in the placebo group. Patients taking orlistat subsequently regained 3.2 kg in the second year compared with 5.6 kg in the placebo group.
          Side effects of orlistat include steatorrhea, flatus, fecal incontinence and oily spotting. These effects are more dramatic with the consumption of fatty foods and may contribute to weight loss by discouraging dietary indiscretion.
          Ephedrine and the xanthines, such as caffeine and theophylline, increase metabolic rate. Studies have demonstrated their efficacy as short-term weight loss medications, but the risk of cardiac complications from hypertension, increased heart rate, increased myocardial oxygen consumption and increased cardiac output limit their clinical use. Thyroid hormone also increases the metabolic rate, but it can cause tachycardia and is associated with accelerated protein loss. Moreover, its effect on weight loss is minimal. It is not recommended as a weight loss medication.
          Other Drugs. Leptin, a hormone produced by fat cells, controls food intake and energy expenditure. In obese persons who are losing weight without medications, a decrease in weight is associated with a decrease in circulating levels of leptin, suggesting its role in weight homeostasis. Obese patients with high leptin levels are thought to have peripheral leptin resistance secondary to the down-regulation of leptin receptors³². It was hoped that administering leptin would stimulate weight loss, but peripherally administered leptin has been found to have no effect.

5.6     Surgical Therapy
Gastroplasty
          Surgical therapy for obesity is usually considered only for persons with morbid obesity in whom more conservative forms of treatment have been unsuccessful although it is combined with dietary, and often with behavioural therapy. Vertical band gastroplasty is currently considered to be the most effective and safest of all gastric lumen reducing procedures³³.

Liposuction
          The concept behind liposuction seems almost too good to be true: Unwanted fat deposits can simply be sucked out with a tiny vacuum. This popular procedure isn't an easy fix, though. Liposuction is a serious surgical procedure that involves a potentially painful recovery and risks of rare but serious complications - even death.
          The areas most commonly treated are the outer thighs and abdomen in women and the flanks in men. Liposuction can also remove unwanted fat from your hips, buttocks, knees, upper arms, chin, cheeks, neck, etc.
          Liposuction is most effective for removing localized fat deposits in parts of your body that dont respond to dieting or exercising. After the procedure you should continue with an exercise and weight management program for best results.

Techniques
          There are two basic techniques used in liposuction: tumescent and ultrasonic. Both techniques share core surgical elements. In fact, even if ultrasound is used, it will be followed by tumescent liposuction. Whether you use tumescent or ultrasonic liposuction depends on a number of individual factors that your surgeon will discuss with you.

Risks
          In general, the larger the volume of fat removed, the higher the potential for complications¹⁸.
          Some surgeons will suction a greater amount of fat at one time and complete the job in one procedure, whereas others will suction smaller volumes over the course of multiple procedures. Ask your surgeon which course he or she follows.

In addition, you are at increased risk of complications from liposuction if you have:

• Diabetes

• Poor circulation

• Heart, lung or liver disease

You are also at increased risk if you:

• Smoke

• Are subject to blood clots

• Take certain medications affecting your liver's ability to metabolize drugs

This increased risk is the same as what you would expect with any surgical procedure under these conditions.

6.       Treatment of Childhood Obesity
          Obesity treatment programs for children and adolescents rarely have weight loss as a goal. Rather, the aim is to slow or halt weight gain so the child will grow into his or her body weight over a period of months to years. Dietz estimates that for every 20 percent excess of ideal body weight, the child will need one and one-half years of weight maintenance to attain ideal body weight.
          Early and appropriate intervention is particularly valuable. There is considerable evidence that childhood eating and exercise habits are more easily modified than adult habits. Three forms of intervention include:

6.1      Physical Activity
          Adopting a formal exercise program, or simply becoming more active, is valuable to burn fat, increase energy expenditure, and maintain lost weight. Most studies of children have not shown exercise to be a successful strategy for weight loss unless coupled with another intervention, such as nutrition education or behavior modification. However, exercise has additional health benefits. Even when children's body weight and fatness did not change following 50 minutes of aerobic exercise three times per week, blood lipid profiles and blood pressure did improve³⁴.

6.2     Diet Management
          Fasting or extreme caloric restriction is not advisable for children. Not only is this approach psychologically stressful, but it may adversely affect growth and the child's perception of "normal" eating. Balanced diets with moderate caloric restriction, especially reduced dietary fat, have been used successfully in treating obesity. Nutrition education may be necessary. Diet management coupled with exercise is an effective treatment for childhood obesity.

6.3     Behavior Modification
          Many behavioral strategies used with adults have been successfully applied to children and adolescents: self-monitoring and recording food intake and physical activity, slowing the rate of eating, limiting the time and place of eating, and using rewards and incentives for desirable behaviors³⁵. Particularly effective are behaviorally based treatments that include parents. Graves, Meyers, and Clark used problem-solving exercises in a parent-child behavioral program and found children in the problem-solving group, but not those in the behavioral treatment-only group, significantly reduced percent overweight and maintained reduced weight for six months. Problem-solving training involved identifying possible weight-control problems and, as a group, discussing solutions.

7.       Prevention of Childhood Obesity
          Obesity is easier to prevent than to treat, and prevention focuses in large measure on parent education. In infancy, parent education should center on promotion of breastfeeding, recognition of signals of satiety, and delayed introduction of solid foods. In early childhood, education should include proper nutrition, selection of low-fat snacks, good exercise/activity habits, and monitoring of television viewing. In cases where preventive measures cannot totally overcome the influence of hereditary factors, parent education should focus on building self-esteem and address psychological issues³⁶.

• Let your child know he or she is loved and appreciated whatever his or her weight. An overweight child probably knows better than anyone else that he or she has a weight problem. Overweight children need support, acceptance, and encouragement from their parents.

• Focus on your child's health and positive qualities, not your child's weight.

• Try not to make your child feel different if he or she is overweight but focus on gradually changing your family's physical activity and eating habits.

• Be a good role model for your child. If your child sees you enjoying healthy foods and physical activity, he or she is more likely to do the same now and for the rest of his or her life.

• Realize that an appropriate goal for many overweight children is to maintain their current weight while growing normally in height.

• Start a weight-management program

• Change eating habits (eat slowly, develop a routine)

• Plan meals and make better food selections (eat less fatty foods, avoid junk and fast foods)

• Control portions and consume less calories

• Increase physical activity (especially walking) and have a more active lifestyle

• Know what your child eats at school

• Eat meals as a family instead of while watching television or at the computer

• Do not use food as a reward

• Limit snacking

• Attend a support group (e.g. weight watchers, overeater anonymous)

          Obesity frequently becomes a lifelong issue. The reason most obese adolescents gain back their lost pounds is that after they have reached their goal, they go back to their old habits of eating and exercising. An obese adolescent must therefore learn to eat and enjoy healthy foods in moderate amounts and to exercise regularly to maintain the desired weight. Parents of an obese child can improve their child's self esteem by emphasizing the child's strengths and positive qualities rather than just focusing on their weight problem³⁷.

CONCLUSION :
          The evidence is now overwhelming that obesity, defined as excessive storage of energy in the form of fat, has adverse effects on health and longevity. Obesity is clearly associated with hypertension, hypercholesterolemia, NIDDM, and excess of certain cancers and other medical problems. Height and weight tables based on mortality data or the body mass index are helpful measures to determine the presence of obesity and the need for treatment. Thirty-four million adult Americans have a body mass index greater than 27.8 (men) or 27.3 (women). At this level of obesity, which is very close to a weight increase of 20 percent above desirable, treatment is strongly advised. When diabetes, hypertension, or a family history for these diseases is present, treatment will lead to benefits even when lesser degrees of obesity are present.
          There is much concern about the increasing prevalence of obesity in children and adolescents. Overweight and obesity acquired during childhood or adolescence may persist into adulthood and increase the risk for some chronic diseases later in life. Teenaged boys lose some fat accumulated before puberty during adolescence, but fat deposition continues in girls. Thus, without measures of sexual maturity, measures of body fat and body weight are difficult to interpret in children and adolescents. Therefore, the objective to reduce the prevalence of overweight and obesity among children and adolescents has a target set at no more than 5 percent and uses the gender- and age- specific 95th percentile of BMI³⁸. Interventions need to recognize that obese children may also experience psychological stress. The reduction of BMI in children and adolescents should be achieved by emphasizing physical activity and a properly balanced diet so that healthy growth is maintained. Additional research is needed to better define the prevalence and health consequences of overweight and obesity in children and adolescents and the implications of such findings for these persons as they become the next generation of adults.
          There is insufficient evidence at this time to recommend the inclusion or exclusion in a routine physical examination of BMI measurement for persons aged 18-65, given the lack of long-term effectiveness of weight reduction therapy in the large majority of obese persons. Weight reduction can be cautiously recommended in obese persons with coexistent diseases who may benefit from weight loss, after taking into account the high recidivism rate and adverse effects of weight loss. For all persons, who are either obese or in the upper normal BMI range and in whom weight reduction is not indicated or has been unsuccessful, maintenance of a stable weight would be a reasonable alternative.
          Obesity research efforts should be directed toward elucidation of biologic markers, factors regulating the regional distribution of fat, studies of energy regulation, and studies utilizing the techniques of anthropology, psychiatry, and the social sciences³⁹.

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