By Dr. Brian McDonough

By Dr. Brian McDonough, Medical Editor

PHILADELPHIA (CBS) – It is an interesting question. Is it better to lose weight over a long period of time or quickly?

READ MORE: SEPTA Union Unanimously Approves Strike If Deal Isn't Reached

A new study in the journal The Lancet looked at 200 Australian men and women who were put into two groups: a 12-week rapid weight loss or a 36-week gradual program. They were both designed to help the participants lose 15 percent of their body weight.

READ MORE: Double Shooting In Eastwick Kills 25-Year-Old Man, Wounds Pregnant Woman: Police

The rapid weight loss group was more successful but here is the interesting news: patients in both groups regained about 70 percent of the weight within two and a half years.

MORE NEWS: 'I Want To Go To Class': Philadelphia Students, Parents On Edge As Possible SEPTA Strike Could Force Virtual Learning

Here is the crucial point. It is well documented that these aggressive diets are extremely difficult to maintain long term. The authors suggest the best chance for long term success is a diet that can be sustained because once calories in the diet increase there is inevitable weight gain.