The Initial Goal of weight loss strategy for overweight users is a reduction in body weight of about 10 percent. If this target is achieved, consideration may be given to further weight loss. In general, people will wish to lose more than 10 percent of body weight; they will need to be counseled about the appropriateness of this initial goal. Further weight loss can be considered after this initial goal is achieved and maintained for 6 months. The rationale for the initial 10-percent goal is that a moderate weight loss of this magnitude can significantly decrease the severity of obesity associated risk factors. It is better to maintain a moderate weight loss over a prolonged period than to regain weight from a marked weight loss. The latter is counterproductive in terms of time, cost, and self-esteem. Rate of Weight Loss A reasonable time to achieve a 10-percent reduction in body weight is 6 months of therapy.

    To achieve a significant loss of weight, an energy deficit must be created and maintained. Weight should be lost at a rate of 1 to 2 pounds per week, based on a caloric deficit between 500 and 1,000 kcal/day. After 6 months, theoretically, this caloric deficit should result in a loss of between 26 and 52 pounds. However, the average weight loss actually observed over this time is between 20 and 25 pounds. A greater rate of weight loss does not yield a better result at the end of 1 year.

    It is difficult for most people to continue to lose weight after 6 months because of changes in resting metabolic rates and problems with adherence to treatment strategies. Because energy requirements decrease as weight is decreased, diet and physical activity goals need to be revised so that an energy deficit is created at the lower weight, allowing the patient to continue to lose weight. To achieve additional weight loss, the patient must decrease calories and/or increase physical activity. Many studies show that rapid weight reduction is almost always followed by gain of the lost weight. Moreover, with rapid weight reduction, there is an increased risk for gallstones and, possibly, electrolyte abnormalities.