get "more" calories b/c of exercise

I'm interested in the reply to this also, as I see eating back the exercise calories as kind of defeating the purpose

MFP includes a calorie deficit in your daily goal. Chances are, you wanted to lose 2lbs/week (which is often too aggressive), so you have to have a deficit of 7,000 calories a week.

To do this, MFP gave you the 1200/day. This is what you would have to eat to create a 7,000 cal/week deficit if you did no exercise and only laid in bed all day. If you burn a further 600 calories with exercise, you are now 1) essentially trying to work on 600 calories a day, which is no bueno; and 2) You have also increased your deficit by 600, to 7,600 per week. Do this every day, and you're at a deficit of 10,600 calories/week and in theory losing 3lbs per week. this might sound great, but you're also not meeting your nutritional goals at 600 cals/day. It will work for a time. You will lose weight. However, you will lose muscle (conventionally you need 0.8-1g protein per pound of lean body mass to maintain, at 4 calories per gram). You will then start to lose hair and have brittle nails. You will lose energy.

So its up to you. You can do it this way, lose a lot of weight, not look the way you want, and become another person back here in 4 months complaining about how they are at their goal weight but still look fat, or you can more slowly, and get the results you want.

The reason for doing exercise is that it improves your health.

But if you exercise and create too big of a deficit by not eating back those calories, you aren't helping your health. So you have it backwards:not eating back your exercise calories defeats the purpose of exercising.