Most people's primary motivation for weight management is to improve their appearance. Equally important, however, are the many other benefits of proper nutrition and regular exercise.

Weight management through reduction of excess body fat plays a vital role in maintaining good health and fighting disease. In fact, medical evidence shows that obesity poses a major threat to health and longevity. (The most common definition of obesity is more than 25 percent body fat for men and more than 32 percent for women.) An estimated one in three Americans has some excess body fat; an estimated 20 percent are obese.

Excess body fat is linked to major physical threats like heart disease, cancer, and diabetes. (Three out of four Americans die of either heart disease or cancer each year; according to the National Health and Nutrition Examination survey, approximately 80 percent of those deaths are associated with life-style factors, including inactivity.)

For example, if you're obese, it takes more energy for you to breathe because your heart has to work harder to pump blood to the lungs and to the excess fat throughout the body. This increased work load can cause your heart to become enlarged and can result in high blood pressure and life-threatening erratic heartbeats.

Obese people also tend to have high cholesterol levels, making them more prone to arteriosclerosis, a narrowing of the arteries by deposits of plaque. This becomes life-threatening when blood vessels become so narrow or blocked that vital organs like the brain, heart or kidneys are deprived of blood. Additionally, the narrowing of the blood vessels forces the heart to pump harder, and blood pressure rises. High blood pressure itself poses several health risks, including heart attack, kidney failure, and stroke. About 25 percent of all heart and blood vessel problems are associated with obesity.

Clinical studies have found a relationship between excess body fat and the incidence of cancer. By itself, body fat is thought to be a storage place for carcinogens (cancer-causing chemicals) in both men and women. In women, excess body fat has been linked to a higher rate of breast and uterine cancer; in men, the threat comes from colon and prostate cancer.

There is also a delicate balance between blood sugar, body fat, and the hormone insulin. Excess blood sugar is stored in the liver and other vital organs; when the organs are "full," the excess blood sugar is converted to fat. As fat cells themselves become full, they tend to take in less blood sugar. In some obese people, the pancreas produces more and more insulin, which the body can't use, to regulate blood sugar levels, and the whole system becomes overwhelmed. This poor regulation of blood sugar and insulin results in diabetes, a disease with long-term consequences, including heart disease, kidney failure, blindness, amputation, and death. Excess body fat is also linked to gall bladder disease, gastro-intestinal disease, sexual dysfunction, osteoarthritiis, and stroke.

Reducing Body Fat Reduces Disease Risk

The good news is that reducing body fat reduces the risk of disease. At the University of Pittsburgh, researchers studied 159 people as they followed a weight management program. The subjects were under age 45 and 30-70 pounds overweight. Those subjects who were able to shed just 10-15 percent of their weight and keep it off during the 18-month study showed significant improvement in HDL cholesterol and triglyceride levels, waist-to-hip ratio, and blood pressure. In fact, according to the New England Journal of Medicine, body fat reduction is a more powerful modulator of cardiac structure than drug therapy.

For people with a family history of heart disease, an active lifestyle can slow or stop the process for all but those with serious genetic disorders. Studies by Dean Ornish, MD, have shown that a comprehensive intervention program that includes regular physical activity, a low-fat diet and a stress reduction program can even reverse the heart disease process.

Evidence also shows that an active lifestyle and its help in reducing body fat is associated with a reduced risk for some types of cancers: prostate for men, breast and uterine cancers for women. (Frisch, et al 1985)

In addition, regular physical activity and a low-fat diet are successful in treating non-insulin dependent diabetes (NIDDM); for some patients, it has reduced or eliminated the need for insulin substitutes. In general, regularly active adults have 42 percent lower risk of developing NIDDM.

Gaining Weight Happens to Most of Us

The average American gains at least one pound a year after age 25. Think about it. If you're like most Americans, by the time you're 50, you're likely to gain 25 pounds of fat, or more. In addition, your metabolism is also slowing down, causing your body to work less efficiently at burning the fat it has. At the same time, if you don't exercise regularly, you lose a pound of muscle each year. Consequently, people are not only increasing their body fat stores, increasing their risk of disease, but they're also losing muscle, increasing the risk of injury, decreasing activity performance, and further slowing down metabolism.

Very few Americans exercise in any significant way. The President's Council on Physical Fitness and Sports estimates that only one in five Americans exercises for the healthy minimum of 20 minutes, three or more days a week. In fact, the average American gets less than 50 minutes of exercise per week. Even worse, two out of five Americans are completely sedentary.

The Answer: Healthy Eating and Physical Fitness

But there is hope. Moderate weight loss--of fat, not muscle--and a healthy and active lifestyle--not dieting--have been found to lower health risks and medical problems in 90 percent of overweight patients, improving their heart function, blood pressure, glucose tolerance, sleep disorders, and cholesterol levels, as well as lowering their requirements for medication, lowering the incidence and duration of hospitalization, and reducing post-operative complications eight times less likely to die from cancer than the unfit, and 53 percent less likely to die from other diseases. Fit people are also eight times less likely to die from heart disease.

So, are you willing to be patient and make gradual changes in your life that will lead to a healthier, happier you? Once you have made the decision to go forward and accept change, the hard part is over. Sure, there is plenty of work to be done, but it really doesn't matter how long this new process takes. If you allow changes to take place over several years, your body will adjust comfortably, and you will be more likely to maintain the healthy lifestyle permanently.

When you begin achieving improvements in energy and physical and psychological performance, the fun and excitement you experience will make the change well worth the effort. Action creates motivation! Good luck: I hope you enjoy all the wonderful benefits of a safe and effective weight management program.

Chad Tackett is President of Global Health & Fitness. Learn how you can have your own personal online trainer, dietician and motivator at http://www.global-fitness.com