Strategies To Lose Weight Fast

I currently weigh 108 pounds at the age of 15, i used to weigh 143 pounds but lost a lot of weight in a very short space of time, around 3 months. I ate very little and now i eat more however still very small amounts. I have been to doctors who say i am underweight and have a low bmi. However, my ankles are still big and i would really like to know how to lose weight on my ankles without having to eat 500 calories a day. Please help!

I’m 14 years old 5 ft 8 in and I weigh 95 pounds. At my height and age I am I am supposed to weigh at least 115 pounds but I need to lose 5 pounds to play this role that I was cast in in a touring theater company. I’ve been having so much trouble losing the weight and everyone says it’s bc I’m already underweight
Anyone know anything that may help?

1 I need to lose 7 pounds. I already do 18 hours of gymnastics monday through friday but I don’t workout on the weekend. (Its my time to rest.)
2 How do I change my diet and stop eating unhealthy snacks inbetween lunch and dinner and after dinner.
3 If I go to a 1200 healthy diet 6 out of the 7 days a week about how long will it take me to lose 7 pounds?