Focus on the long term. Diets fail when people fall back into poor eating habits; maintaining weight loss over the long term is exceedingly difficult. Most people regain the weight they've lost. In fact, some studies indicate that 90 to 95 percent of all dieters regain some or all of the weight originally lost within five years. Your program should include plans for ongoing weight maintenance, involving diet, exercise and a behavioral component. While there are some physical reasons for obesity, there are also behavioral reasons for excessive eating. For example, many women use food as a source of comfort (perhaps to deal with stress). For these women, a weight loss program with a behavioral component will offer alternatives to replace food in this role.
If you lose weight suddenly or for unknown reasons, talk to your health care professional immediately. Unexplained weight loss may indicate a serious health condition. And even if it doesn't, simply being underweight is linked to menstrual irregularity, menstrual cessation (and sometimes, as a result, dental problems, such as erosion of the enamel and osteoporosis) and a higher risk of early death.