Open Question: What is a good way for an active dancer to lose a lot of weight over the summer?

I'm 15 years old and will be 16 in November. I was on varsity Poms last year (i will be on varsity again next year) and have done ballet for 13 years now. As I get into more intense training as well as participate in more intense competitions, i have had issues with my weight. I weigh A LOT (182 lb) and am about 5' 10" tall. Last year at nationals for Poms the judges docked our score due to my 'chunkyness'. This is causing a lot of issues for me and i would prefer for the benefit of my health and for my team to lose some weight and become quite a bit more trim. any advice?