What happens if I can't meet my calorie intake???

OK, this will be long. Please read it if you are confused. Disclaimer: I am not a dietician or a doctor, just a successful loser and maintainer, who has consulted both doctors and dieticians.

Question #1:

Should I eat all my calories?

Yes. MFP is already figuring a deficit for you to lose weight. This deficit is based on what you need to eat based on your everyday activity, not counting exercise. In the end, it's all about "net calories" (you can view yours under reports)

Example: you need to eat 2,000 calories to maintain your current weight (random number)
MFP will tell you to eat 1,500 to lose one pound per week (500x7=3500=one pound loss).

Let's say you exercise, and burn 500 additional calories.
UH-OH, now you are at a 1,000 calorie a day deficit. You need 2,000 calories to maintian, are already restricted to 1500, so now your net calories are a 1,000 a day. This is starvation central. Your body, which is very good at keeping you alive, will store and save calories. You WILL stop losing weight. You WILL want to throw your scale out the window.

Eat your exercise calories. At least eat most of them.

Question #2:
I'm eating 1200 calories, I feel like crap and I'm not losing weight. What gives?

Answer:
Run, don't walk, to "tools" and use the BMR calculator. Please, please, please, eat at least your BMR calories every day. You might lose weight more slowly, but you will still lose, and you will not longer feel a sudden urge to fall over every time you do, well, anything.

Question #3:
I'm doing "everything right" and the scale won't move.

Answer #1: The scale is the devil. Step away from the scale. Buy a tape measure, notice how your clothes are (probably) fitting better. Muscle is more dense than fat, and takes up less space on your body. More muscle on your body will make the scale freeze or (gasp) move upward.

Answer #2: You're not being honest. In order for this to work, you must record every morsel of food that goes in your body. Also, if you ride a stationary bike for 30 minutes and barely break a sweat and can still chatter on your cell phone (OK, that's my personal gym pet peeve) then you're probably not working "vigorously". Don't overestimate your exercise calories. (this was a big mistake I made in the past.)

Answer #3: Your body might be re-adjusting. How you feel is the most important mark of progress. It's very easy to fixate on numbers, but feeling better really should be its own reward.

Question #4:
So, if I'm eating my exercise calories, what's the point of exercise?

Answer: (warning: extremely opinionated answer ahead)
You don't. You can lose weight through diet alone. But, then you will be skinny and flabby. Is a model skinnier than me? OH, YES! Is she healthier than me? probably NOT. She couldn't survive the hour-long spin class that I take three times a week. Trust me. Her skin is a mess, she smokes, and she looks like crap in person.

It's 10:23am here, I just burned 770 calories running, and MFP is saying I need to consume 2600 calories. It just feels like so much! I could probably eat that much before lunch if it was junk food, but I'm struggling to think of foods that are healthy and get me to that number without constantly eating for the next 12 hours!

yup! Thats my problem..maybe we need to eat double our calories at morning then...protien shakes, eggs, and carbs...maybe that will help...in order to keep the dinner low calories...(i like to do my salads with black beans at night...so its not so heavy and ruining my workouts...)

Yep. Most things I've read have said that if you are working out/training in the evening, you should eat your biggest meal at breakfast and taper down as the day goes on.

The best way to get all your calories is to plan ahead. Just because you work out in the evening, doesn't mean you should be eating all your calories you burn after your exercise. If you know you're going to have an extra 500 calories from exercise in the evening, add another 200 calories to your breakfast, another 200 to your lunch and 100 as a post-workout recovery. Your body will process the calories more efficiently than having to process 500 calories post workout (big glob of food going in all at once). It's like drinking water consistently throughout the day vs. gulping 2L at the end of the day.