 calatrin has been helping people lose weight safely since 1997 so we're talking about almost 30 years of healthy weight loss there's no rebound weight gain with this product this is not something that works against your body it's not trying to retrain your body to it doesn't do anything weird like this is just your body burning off fats and sugars more efficiently like it did when you were younger so what it does is it rebuilds lean muscle tissue it's rubbing up your metabolism that way it