Actually, the term overweight includes muscle, bone, fat, and water, but the term obese specifically refers to an excessive amount of body fat. Some very muscular people may be considered overweight without being obese.

Calories are stored as body fat when a person consumes more calories than he or she burns off. The cause of calorie imbalance differs from person to person. However, genetic, environmental, psychological, and other factors are known to contribute to obesity.

Body mass index (BMI) is used to measure the relationship (or ratio) of a person's weight and height. A BMI is more closely equated with body fat than other measures of height and weight. A BMI of 25 to 29.9 is considered overweight; a BMI over 30 is considered obese. Experts may measure waist circumference to determine abdominal fat, and a waist-to-hip ratio may also be calculated.

In addition to family history of certain chronic diseases such as heart disease and diabetes, high blood pressure, high cholesterol levels, or high blood sugar are all warning signs of health problems that can occur with obesity.

People that are obese are at increased health risk for many diseases such as heart disease, type 2 diabetes, high blood pressure, stroke, gall bladder disease, and osteoarthritis. In women, obesity is associated with cancer of the uterus, gallbladder, cervix, ovary, breast, and colon. In men, obesity is linked to cancers of the colon, rectum, and prostate.

Actually, losing as little as 5 percent to 10 percent of body weight can improve health problems linked to obesity, such as high blood pressure and diabetes. The initial goal for weight loss for overweight or obese people should be to reduce body weight by about 10 percent from baseline.

A diet that severely restricts a person's food choices and/or intake is not usually recommended. The healthiest way for individuals to begin losing weight is to work with a registered dietitian who can assess the type of diet needed for initial weight loss. In addition, moderate levels of physical activity for 30-45 minutes, 3 to 5 days a week should be part of a comprehensive weight loss program.

Experts say that your success with weight loss will depend on your level of obesity, overall health condition, and motivation to lose weight. Treatment may include a combination of diet, exercise, behavior modification, and sometimes weight-loss drugs. In some cases of severe obesity, gastrointestinal surgery may be recommended.