net calories

Eating less number of calories makes you unhealthy and sick. So, you must eat required number of calories- these depends on the gender; females must multiple their weight by 12 and males must multiple their weight by 15.

The calorie target that MFP sets for you is already at a deficit to what your body is burning, that's why you should make sure that your net calories are as close as possible to your target. One day doesn't make a difference, but if you consistently eat a caloric amount that's too low you can risk slowing your metabolism and inhibiting fat loss.

^^ this

Are you EATING more than 1200 but then your exercise takes the net figure below that? I think that's less of a problem than actually eating below 1200, where your body will struggle to get all the nutrients it needs.

I believe the opposite - Your body goes in to starvation mode if your NET cals are under.
So, if you burned 300 cals doing exercise, you should eat 1500.

I recently changed my settings to losing 1/2 pound per week, so my intake is now 1370,
and I EAT ALL extra exercise cals.

So I'm actually eating between 1600-1900.

Since I did that, I'm losing weight FASTER, because my body trusts that I'm going to feed it.

But I don't use MFP's exercise cal info. I use beats per minute to calculate calorie burn,
and I record NET burn, not GROSS burn.

Here's a link to a site that does that for you -
http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx