Insanity and nutrition.

Since I started Month 2 of insanity and I've a really big problem! I burn tons of calories and I end up with Low net calories! Idk what to do. I eat alot and track every single bite but my calories aren't high enough cause I always burn 400-600 calories and some times 800. if any one could help me. I'd really be so thankful cause I don't want this low net calorie, please.