When do you overeat?  LCD's (little chocolate donuts) for breakfast? Fast food for lunch? Ice cream before bedtime?  In this episode of Second Opinion, we'll learn about the interaction of genes and the environment, and learn to eat sensibly, exercise regularly, and manage stress. The result? A healthy lifestyle in which weight loss is simply a natural by-product.

If you weigh more than you should, you are definitely not alone. According to the Centers for Disease Control, overweight and obesity are serious health problems that have increased at an epidemic rate over the past two decades. And many healthcare professionals feel the situation may get worse before it gets better.

According to one key study, approximately 127 million adults in the U.S. are overweight, including 60 million people who are obese and 9 million who are severely obese. However, the problem does not end there. Even among children and teens ages 6 to 19, almost 9 million are overweight, a number that has tripled since 1980. And studies show that many overweight children and adolescents grow up to be overweight or obese adults.

Your body weight can literally be a matter of life or death. Every year, about 280,000 women and men die prematurely from causes linked to obesity. People who are obese are at greater risk of developing serious medical conditions which can contribute to ill health and early death. It has also been established that the more obese you are, the greater your risk. Among the more serious problems linked to obesity are type 2 diabetes, heart disease, high blood pressure, osteoarthritis, and even certain types of cancer.

Overeating and lack of exercise are the primary causes of overweight and obesity, especially when the two are combined. But there are many factors that may contribute to the problem. These include:

• Diet. Regular consumption of fast foods, soft drinks, candy, desserts, and other high-fat or sugary foods that are high in calories contribute to weight gain.
• Inactivity. People who get little or no exercise burn fewer calories than they take in, and are more likely to gain weight.
• Genes. If one or both of your parents are obese, you have an increased chance of being overweight yourself. But your genetic makeup does not guarantee that you will be obese.
• Gender. Men burn up to 20% more calories than women do, and they generally have an easier time staying at a healthy weight.
• Psychological factors. Some people eat more than they should to cope with stress, problems, and emotional distress.
• Age. As you get older, your muscle mass decreases and fat accounts for a greater percentage of your weight. In addition, your metabolism slows and you tend to be less active, so your body needs fewer calories to function. But if you don't reduce the number of calories you take in, you will probably put on weight.
• Pregnancy. After each pregnancy, a woman's weight increases by an average of four to six pounds.
• Cigarette smoking. When you quit smoking cigarettes, your metabolism slows because you are no longer getting nicotine, so you burn fewer calories. Additionally, food begins to taste and smell better, and you may gain weight because you eat more.
• Medications. Tricyclic antidepressants, corticosteroids, and some other medicines can influence weight gain.
• Medical issues. Low thyroid function, excess hormone production by the adrenal glands (Cushing's syndrome), and other medical problems directly account for only a small percentage of obesity cases. However, medical problems that lead to decreased activity can easily result in weight gain.

The good news is that losing even small amounts of weight can lower your blood pressure and reduce your risk of heart disease, stroke, diabetes, and other medical problems. While there are many safe and effective ways to lose weight, many people are drawn to slickly marketed fad diets and "miracle cures" that may do more harm than good. The best way to approach weight loss is with the help of your doctor.