P90X3 Diet Plan Question

Hello all, I have a question about the caloric intake recommendations in the P90X3 plan. I've been losing inches quite comfortably on 1400/day with very little exercise, and I wanted to actually start getting fit. Many people recommended P90X3 as it's had great results and is only 30 minutes a day, and includes modifications if you're not quite up to scratch yet. I got a copy for a very good price and aim to start it in the next day or two.

My concern is that after taking the nutrition quiz in the booklet, it says I should be eating 2100/day while doing the programme. I'm a 5'2 female that weighs roughly 180lbs, (possibly less, I don't weigh myself, I take inches these days) and a hike of 700 calories seems a lot for 30 minutes of exercise a day, and I doubt I'll be burning that much during each workout.

Can anyone explain how I'd still lose fat on this plan? Thanks in advance.