I am nw 21stone and want to get down to about 12stone and realy want to try gastric balloon would it help me?

Stick to basics: There is no substitution for a healthy, well-balanced diet, regardless if the goal is weight gain or loss.Weight gain is achieved if the individual takes in more calories than he/she burns; weight loss happens when calories burned exceed calorie intake. If you get the gastric balloon ; lose weight, you have not learned how to avoid regaining unwanted weight once the balloon is removed. Basics pls.