Obesity is an abnormal accumulation of body fat, usually 20% or more over an individual’s ideal body weight. Obesity is associated with increased risk of illness, disability, and death. Obesity traditionally has been defined as a weight at least 20% above the weight corresponding to the lowest death rate for individuals of a specific height, gender, and age (ideal weight). Twenty to forty percent over ideal weight is considered mildly obese; 40–100% over ideal weight is considered moderately obese; and 100% over ideal weight is considered severely, or morbidly, obese. More recent guidelines for obesity, use a measurement called BMI (body mass index) which is the individual’s weight multiplied by 703 and then divided by twice the height in inches. BMI of 25.9–29 is considered overweight; BMI over 30 is considered obese. Measurements and comparisons of waist and hip circumference can also provide some information regarding risk factors associated with weight. The higher the ratio, the greater the chance for weight associated complications.
The World Health Organization terms obesity a worldwide epidemic, and the diseases that can occur due to obesity are becoming increasingly prevalent. Excessive weight can result in many serious, potentially life-threatening health problems, including hypertension, Type II diabetes mellitus (non-insulin dependent diabetes), increased risk for coronary disease, increased unexplained heart attack, hyperlipidemia, infertility, and a higher prevalence of colon, prostate, endometrial, and, possibly, breast cancer. Approximately 300,000 deaths a year are attributed to obesity.
Causes and symptoms:
The mechanism for excessive weight gain is clear— more calories are consumed than the body burns, and the excess calories are stored as fat (adipose) tissue. However, the exact cause is not as clear and likely arises from a complex combination of factors. Genetic factors significantly influence how the body regulates the appetite and the rate at which it turns food into energy (metabolic rate). Studies of adoptees confirm this relationship—the majority of adoptees followed a pattern of weight gain that more closely resembled that of their birth parents than their adoptive parents. A genetic predisposition to weight gain, however, does not automatically mean that a person will be obese.
Eating habits and patterns of physical activity also play a significant role in the amount of weight a person gains. Recent studies have indicated that the amount of fat in a person’s diet may have a greater impact on weight than the number of calories it contains. Carbohydrates like cereals, breads, fruits, and vegetables and protein (fish, lean meat, turkey breast, skim milk) are converted to fuel almost as soon as they are consumed. Most fat calories are immediately stored in fat cells, which add to the body’s weight and girth as they expand and multiply. A sedentary lifestyle, particularly prevalent in some affluent societiescan contribute to weight gain. Psychological factors, such as depression and low self-esteem may, in some cases, also play a role in weight gain.
At what stage of life a person becomes obese can affect his or her ability to lose weight. In childhood, excess calories are converted into new fat cells (hyper-plastic obesity), while excess calories consumed in adulthood only serve to expand existing fat cells (hypertrophic obesity). Since dieting and exercise can only reduce the size of fat cells, not eliminate them, persons who were obese as children can have great difficulty losing weight, since they may have up to five times as many fat cells as someone who became overweight as an adult. Obesity can also be a side effect of certain disorders and conditions, including:
• Cushing’s syndrome, a disorder involving the excessive release of the hormone cortisol.?
• Hypothyroidism, a condition caused by an underactive thyroid gland ?neurologic disturbances, such as damage to the hypothalamus, a structure located deep within the brain that helps regulate appetite. ?
• Consumption of certain drugs, such as steroids or anti-depressants.
The major symptoms of obesity are excessive weight gain and the presence of large amounts of fatty tissue. Obesity can also give rise to several secondary conditions, including: ?
• Arthritis and other orthopedic problems, such as lower back pain. ??
• High cholesterol levels. ?
• High blood pressure. ?
• Decreased fertility, and pregnancy complications. ??
• Sleep apnea and sleeping disorders. ?
• Emotional and social problems.
Diagnosis of obesity is made by observation and by comparing the patient’s weight to ideal weight charts. Many doctors and obesity researchers refer to the body ?mass index (BMI), which uses a height-weight relation- ship to calculate an individual’s ideal weight and person- al risk of developing obesity-related health problems. Physicians may also obtain direct measurements of an individual’s body fat content by using calipers to measure skinfold thickness at the back of the upper arm and other sites. The most accurate means of measuring body fat content involves immersing a person in water and measuring relative displacement; however, this method is very impractical and is usually only used in scientific studies requiring very specific assessments. Women whose body fat exceeds 30% and men whose body fat exceeds 25% are generally considered obese.
Doctors may also note how a person carries excess weight on his or her body. Studies have shown that this factor may indicate whether or not an individual has a predisposition to develop certain diseases or conditions that may accompany obesity. ‘Apple-shaped’ individuals who store most of their weight around the waist and abdomen are at greater risk for cancer, heart disease, stroke, and diabetes than ‘Pear-shaped’ people whose extra pounds settle primarily in their hips and thighs.
Treatment of obesity depends primarily on how overweight a person is and his or her overall health. However, to be successful, any treatment must affect lifelong behavioral changes rather than short-term weight loss. Behavior-focused treatment should concentrate on:
1. What and how much a person eats: This aspect may involve keeping a food diary and developing a better understanding of the nutritional value and fat content of foods. It may also involve changing grocery-shopping habits (e.g. buying only what is on a prepared list and only going on a certain day), timing of meals (to prevent feelings of hunger, a person may plan frequent, small meals), and actually slowing down the rate at which a person eats.
2. How a person responds to food: This may involve understanding what psychological issues underlie a person’s eating habits. For example, one person may binge eat when under stress, while another may always use food as a reward. In recognizing these psychological triggers, an individual can develop alternate coping mechanisms that do not focus on food.
3. How they spend their time: Making activity and exercise an integrated part of everyday life is a key to achieving and maintaining weight loss. Starting slowly and building endurance keeps individuals from becoming discouraged. Varying routines and trying new activities also keeps interest high.
For most individuals who are mildly obese, these behavior modifications entail lifestyle changes they can make independently while being supervised by a family physician. Other mildly obese persons may seek the help of a commercial weight-loss program (e.g. Weight Watchers). The effectiveness of these programs is difficult to assess, since programs vary widely, dropout rates are high, and few employ members of the medical community. However, programs that emphasize realistic goals, gradual progress, sensible eating, and exercise can be very helpful and are recommended by many doctors. Programs that promise instant weight loss or feature severely restricted diets are not effective and, in some cases, can be dangerous.
For individuals who are moderately obese, medically supervised behavior modification and weight loss are required. While doctors will put most moderately obese patients on a balanced, low-calorie diet (1200–1500 calories a day), they may recommend that certain individuals follow a very-low-calorie liquid protein diet (400–700 calories) for as long as three months. This therapy, however, should not be confused with commercial liquid protein diets or commercial weight-loss shakes and drinks. Doctors tailor these diets to specific patients, monitor patients carefully, and use them for only a short period of time. In addition to reducing the amount and type of calories consumed by the patient, doctors will recommend professional therapists or psychiatrists who can help the individual effectively change his or her behavior in regard to eating.
As many as 85% of dieters who do not exercise on a regular basis regain their lost weight within two years. In five years, the figure rises to 90%. Repeatedly losing and regaining weight encourages the body to store fat and may increase a patient’s risk of developing heart disease. The primary factor in achieving and maintaining weight loss is a life-long commitment to regular exercise and sensible eating habits.
Obesity experts suggest that a key to preventing excess weight gain is monitoring fat consumption rather than counting calories, and some Cholesterol Education Programs maintain that only 30% of calories should be derived from fat. Only one-third of those calories should be contained in saturated fats (the kind of fat found in high concentrations in meat, poultry, and dairy products). Because most people eat more than they think they do, keeping a detailed food diary is a useful way to assess eating habits.
Eating three balanced, moderate-portion meals a day, with the main meal at mid-day is a more effective way to prevent obesity than fasting or crash diets. Exercise increases the metabolic rate by creating muscle, which burns more calories than fat. When regular exercise is combined with regular, healthful meals, calories continue to burn at an accelerated rate for several hours. Finally, encouraging healthful habits in children is a key to preventing childhood obesity and the health problems that follow in adulthood.
(Author is General Practitioner and can be reached at: Mir.firstname.lastname@example.org)