Will eating 1,200 calories help me lose weight?

Hi, so I'm really just looking to loose more of my thigh weight and maybe a little of my waist. I'm 15 I weigh 117 and I and 5'7 I don't know my waist measurement but my thigh measurement is 18 inches. I eat a TON but I have a fast metabolism. But I eat a lot of junk food so I wanna lower my portions and eat healthier foods. So I have this app called my fitness pal and it basically counts my calories and keeps track of what I eat and I was just wondering if I eat 1,200 a day would I loose some weight ?? But I would eat like 6 small healthy snacks throughout the day to keep my metabolism going. Snacks meaning like a yogurt and cheese . If I eat like this with the minimum of 1,200 will I lose some kind of weight ? And if I do lose a good amount of weight if I start eating normal again will I gain more even if I go to the gym?? Because right now I go to the gym every now and then to go on the elliptical for 30 min and the like work on my abs and arms. So my main question is : Even if I eat 6 small healthy snacks that are satisfying with the minimum of 1,200 calories a day and the gym.. Will I lose weight? And also if I love weight and go back to eating normal but still go to the gym.. Will I gain weight since I'm eating normal or will I maintain the weight since I'm at the gym? Thanks 10 points for best answer