Insanity and Nutrition

I've just started Insanity in an effort to shift that last difficult stone and want to make sure that I am eating properly.

As a 202lb 6ft Male I am eating 1490 + around 70% of exercise calories.

Is it safe to keep eating like this while doing insanity or should I be aiming to eat 100% of exercise calories to maintain my muscle mass and promote fat loss.

Any advice on this will be greatly appreciated