Dieters usually do not set out to lose weight for only a few weeks or months at a time. While some may want to lose an extra ten pounds or so for an event, most are looking for substantial, long term success. Researchers have found that the type of diet that is being used may influence how well and how long the lower weight is maintained. Part of the reasoning lies in the way that certain diets increase the speed that calories are burned in the body.

Dr. David Ludwig, the director of the New Balance Foundation Obesity Prevention Center which is a part of the Boston Children's Hospital, was the lead researcher and wrote the accompanying study paper which has been published in the Journal of the American Medical Association. That study focused on dieters who were already doing well in their own process before randomizing them into one of three groups.

A small group of overweight and obese young adults were recruited for the study. Those people, of both genders, were already dieting and had lost between ten and fifteen percent of their starting body weight. For the duration of the study, the adults were asked to follow either a low fat, low carbohydrate or low glycemic index diet plan for a four week period.

At the end of the study, Ludwig found that on the low fat diet, participants had the lowest metabolic rate which led them to also have the lowest and slowest amount of weight loss. The winner, in terms of overall weight loss, was the low carb diet which allowed the study participants to burn 350 more calories per day than the other two groups. The low glycemic index group, whose diet works by stabilizing blood sugar burned roughly 150 additional calories per day.

Ludwig cautioned that the low carb diet, especially some of the more extreme versions may have some very serious, negative side effects including an increase in the stress hormone, cortisol. High levels of cortisol are associated with insulin resistance and an increased risk of heart disease but may also lead to weight retention in the stomach area. Those diet plans may also boost the body's production of a particular type of protein which has also been linked to serious heart disease.

According to prior research studies, people who have lost at least ten percent of their body weight may decrease their metabolic rate so dramatically that they have a hard time keeping the weight off. Only one in six of those people were able to maintain their weight loss for one year or more.