If obesity were merely a matter of aesthetics, it would be of less concern. But obesity is a health issue. It is associated with an increased risk of diabetes, lipid abnormalities, coronary artery disease, high blood pressure, certain cancers (such as breast, colon, and gallbladder in women and colon and prostate in men), stroke, degenerative arthritis, respiratory problems, sleep disturbances, and gallbladder disease. Obesity places a huge burden on society in terms of lost lives, ongoing illnesses, emotional pain, discrimination, and economic cost (nearly $100 billion annually).
The most ominous burdens posed by being overweight are reduction of the quality of life and shortening of life span. The likelihood of dying early (compared with the average age at death of all people in the population) progressively increases the more overweight you are. Diseases caused by obesity are the second leading cause of preventable deaths in the United States.
The "Bulge"
With countless diet programs and products promising to help you shed pounds, losing weight should be easy. Simply eating too much and not being active enough are the causes of most overweight problems. But you also know it is hard to lose weight and even harder to keep it off. The cause of overweight and obesity is a chronic imbalance of calories ingested and calories burned.
Genetic and environmental factors also contribute to obesity. Americans spend more than $33 billion a year on weight-loss products and services, but they are losing the “battle of the bulge.” Despite the great desire of Americans to be thinner, they have become more obese. Some have even declared that the United States has an “obesity epidemic.” It is estimated that more than 50 percent of adult Americans are overweight. The prevalence of obesity also is increasing in several other countries.
"Overweight" and "obesity"
Both are terms that often are used interchangeably, but they have different meanings. "Overweight" refers to having excess body weight compared with the norm for a person’s height, but the term does not account for what tissue is making up the weight. For example, athletes are often overweight according to weight-for-height tables because they have increased muscle mass. However, for most people, overweight means having too much fat. “Obesity” refers to body fat in excess of what is healthful for an individual. In healthy women, an acceptable level of body fat ranges from 25 to 35 percent. In contrast, an acceptable range of body fat in men is from 10 to 23 percent.
The number of calories used by an individual is determined by three factors: basal metabolic rate, the thermic effect of the food eaten, and the calories used during physical activity. The basal metabolic rate is the amount of energy needed to maintain bodily functions when an individual is at rest. This component accounts for 60 to 75 percent of the daily calorie requirement in sedentary adults. The major determinant of the basal metabolic rate is the amount of fat-free mass in the body.
Muscle is one example of fat-free mass. Resistance (strength) training can increase the amount of muscle and therefore increase the basal metabolic rate. Resistance training also can help prevent the loss of lean mass that normally occurs with aging. Men tend to have more muscle than women and therefore burn more calories.
The "thermic" effect of food is the energy required to digest, metabolize, and store nutrients. The thermic effect of food accounts for about 10 percent of the total daily calorie use. The number of calories burned during exercise can vary tremendously depending on the amount of exercise performed. For most so-called sedentary persons, the activities of daily living (such as walking, talking, and sitting) account for 15 to 20 percent of the daily calorie use.
Why you should lose weight?
How do you determine whether you are overweight or obese? Scientists can use sophisticated tests to measure body composition. However, these are not necessary for most individuals. You can measure your change in weight over time. Alternatively, you can calculate your body mass index (BMI) and determine its relationship to health risks.
Marking the Risk
There are risk factors that indicate a predisposition for obesity. Among these risk factors are the following: Body mass index (BMI)—BMI is defined as your weight (in kilograms) divided by the square of your height (in meters). Simpler still, look it up in the table below. The advantage of BMI over bathroom scales and weight-for-height tables is that it normalizes weight for height and helps determine whether you have a healthful or unhealthful percentage of total body fat. People who should not use the BMI for determining health risks include competitive athletes and body builders. Their BMI will be high because they have a larger amount of muscle. BMI is also not predictive of health risks for growing children, women who are pregnant or lactating, and frail, sedentary older adults.
A BMI from 19 to 24.9 is associated with a minimal to low health risk. A BMI from 25 to 29.9 is considered overweight and is associated with moderate health risks. A BMI of 30 or higher is considered obese and is associated with a substantially greater risk for development of various diseases. Extreme obesity is a BMI of more than 40. Body shape—Increasing attention has been focused on the distribution of body fat as a potential indicator of health risk. Specifically, excess fat in the abdomen is associated with an increased risk for development of various metabolic illnesses, including diabetes mellitus, increased blood lipid levels, and high blood pressure.
In contrast, people whose excess fat is located in their lower body (hips, buttocks, and thighs) seem to have minimal or no increased risk of these diseases. Upper-body obesity also is associated with an increased risk for coronary artery disease, stroke, and certain cancers. Therefore, it can be helpful to assess your health risk by measuring your waist circumference. A measurement of more than 35 inches in women and 40 inches in men is associated with increased health risks, especially if you have a BMI of 25 or more.
Knowing that no one lacks from health risks (even the fittest person can have a heart attack, diabetes, or cancer), health and well-being are apt to be in less jeopardy if BMI, body shape, and family health history do not indicate problems. However, if your BMI is 25 or more, if your fat is primarily located in your upper body, and if you have a personal or family history of diabetes, heart disease, high blood pressure, or sleep apnea, losing weight can greatly improve your health.
Keep in mind that BMI and waist circumference are just starting points. Other factors also are important. When in doubt, seek a medical evaluation by your physician. A thorough history, examination, and blood studies can clarify whether your weight is having adverse effects on your health. The appropriate plan of action then can be tailored to meet your individual needs.
Getting Started
Losing body fat and keeping it off are not easy. Losing weight and then maintaining a healthful weight require collaboration with knowledgeable health care professionals. Obesity is not only a medical issue but also is a lifestyle issue. Your habits can help you maintain a desirable body weight or they can hamper your efforts to lose weight or even cause you to gain further weight. The types and amounts of food you eat and the exercise you perform will determine whether you gain, lose, or maintain your weight. Therefore, experts recommend that any weight loss program should consist of three main components: nutrition, exercise (or activity), and behavior modification. See Weight Management Programs below.
Liquid meals, over-the-counter diet pills, and special combinations of foods promising to “burn” fat are not the answers to long-term weight control and better health. Learning to eat differently - to enjoy a well-balanced diet of fewer calories - is the best strategy to achieve health and weight goals. You should begin by substituting the words “healthful nutrition program” for “diet.” Most people try to lose weight by eating 1,000 to 1,500 calories a day. In many instances, eating fewer than 1,400 calories makes it difficult to eat a balanced diet containing the recommended levels of nutrients. Therefore, nutrition programs that are too low in calories may be hazardous to your health.
You can lose weight by eating fewer calories or by increasing exercise. A caloric deficit of 3,500 calories is required to lose 1 pound of fat. Over 7 days, this can be achieved by cutting 500 calories each day from your usual food intake or by cutting 250 calories each day (such as one or two fewer cookies) and burning an additional 250 calories with exercise (such as by walking briskly for 30 minutes). The good news is that a relatively small loss of weight can make a big difference in reducing the risk of health complications from obesity. Even a 10 percent weight loss can lead to improvement in your blood sugar level, lipid values, and blood pressure.
For most people, the volume of food consumed determines how full you feel. Therefore, eating a small amount of an energy-dense food (such as fat) is usually not filling, whereas eating a large enough amount to fill you up results in a very large calorie intake. To lose weight, decrease your total calories by cutting back on the fat while filling up on low-calorie high-nutrient foods such as vegetables, fruits, and grains. You also can eat lower-fat versions of foods. However, be careful, because low-fat is not always low calorie (see Low-Fat Is Not Necessarily Low-Calorie, table below).
Healthful eating habits also avoid the feast or famine phenomenon. Distributing food selections throughout the day provides nourishment to support daily activities and can help to eliminate energy highs and lows. Three meals and occasional snacks also keep one’s appetite in check. It is also important to avoid the hazards of repeatedly losing and gaining weight. Although repeated dieting is still a matter of debate, some studies suggest that it may lower the rate at which calories are burned. When a person is off the diet and more food is eaten, the body stores fat faster and more efficiently. This effect causes regain of the lost weight. In this circumstance, the amount of weight regained often is more than that lost in the first place.
Physical Activity
Improved eating habits in combination with decreased calorie intake and calorie-burning exercise is the best way to lose weight and maintain the results. In addition to enhancing weight loss efforts, physical activity promotes loss of body fat, increases muscle mass, and increases cardiovascular fitness. Regular exercise not only helps you lose weight by increasing the number of calories you burn but also makes it easier to keep off the weight that you have already lost. Walking is a good choice for getting started on an exercise plan. A daily 2-mile walk burns approximately 1,000 to 1,200 calories per week. In addition, do not discount the physical activity that is part of ordinary activities of daily living - housework, climbing stairs, gardening - all important forms of exercise that can contribute to weight loss. It may be easier to maintain a schedule if you exercise with a friend.
Many experts recommend that you also participate in resistance (or strength) training. Resistance training can increase your muscle mass (which, as discussed previously, increases your basal metabolic rate), your bone density (which can help protect against osteoporosis), and your balance and coordination (which can lower the risk of injury), and it can help improve your posture. People who are overweight, have been inactive, or have medical problems should check with their physician before starting an exercise program. An exercise stress test may be helpful because it can measure the response of the heart to exercise and help establish a safe starting level.
A good behavior modification programs help identify triggers and treatments for unhealthful eating habits - such as uncontrolled snacking or late night eating. Such programs often explore the reasons behind an inactive lifestyle. Food diaries and activity logs frequently are used to heighten your awareness of what and how much is eaten and the type and amount of exercise done daily. These journals often provide insight into what triggers undesirable eating and what can be done to avoid or change this behavior. Other key behavioral elements needed for success include: Commitment - There must be personal motivation to change - to eat healthfully and to get regular physical activity. Priorities - It takes significant mental and physical energy to change deeply ingrained habits. If other major issues or life stresses are present, it is important to seek help for dealing with them.
When balance in life is regained, you can focus on healthful nutrition more effectively. Realistic goals - The best goals are those that can be achieved. Set daily or weekly goals that allow progress to be measured and rewarded. Aim to lose about 1 to 2 pounds weekly. It is important to know that small losses of weight - or improvements in physical activity - can improve health. Measurements of blood pressure, blood sugar level, and blood cholesterol and triglyceride values are more important in terms of health than the number on the scale. Accept the fact that there will be setbacks. Instead of becoming frustrated or angry, resume your health program once again. Group support - Joining people facing the same challenges can promote sharing of ideas and facilitate commitment.
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