Daily Calorie Goal

eat at least your BMR (you find this under Tools her on MFP). This is what your body requires just to function. And on days you exercise eat what you burn. You want your NET calories to stay above 1200 and this is why:

http://www.hussmanfitness.org/html/TPAdaptation.html

The law of unintended consequences

Your body is an amazing feedback system aimed at balance and survival. Humans are at the top of the food chain because they are able to adapt to their environment. Every action produces a reaction. Every change in its environment triggers a survival response. It's important to keep that in mind when you plan your fitness program. If you treat your body as an enemy to be conquered, you'll produce unintended results.

For example, if you severely cut off the supply of food to your body, it will defend itself by slowing down its metabolism to survive starvation. The body will shed muscle mass the same way that you would throw cargo from a plane that was low on fuel, and it will reduce its thyroid activity to conserve energy. The body will also actually defend its fat stores. In anorexia, muscle loss can be so profound that fat as a percentage of body weight actually rises. Extreme carbohydrate restriction also causes muscle loss, dehydration, and slower metabolism, which is why even successful Atkins dieters can have a significant rebound in weight after they stop the diet (don't worry – the advice on this site will prevent that from happening).

As another example, if you put your body under stress through overexertion and lack of sleep, it will respond by slowing down, reducing muscle growth, and increasing your appetite for junk food, carbohydrates and fat. If you feed your body excessive amounts of sugar and quickly digested carbohydrates, and it will shut off its ability to burn fat until those sugars are taken out of the bloodstream.

This website will show you how to work with your body to quickly produce the changes you want. In order to do that, you need to take actions that push your body to adapt – to build strength, burn fat, and increase fitness. You need a training program, not an exercise routine. You need a nutrition plan, not a diet. You need a challenge, not a few good habits you usually try to follow except when you don't.
Setting the right goal

John Dewey once said that a problem well-stated is half-solved. If you want to reach your goal, you have to define it correctly. See, a lot of people say “I want to lose weight.” Well, if losing weight is your goal, go on a no-carb diet. You'll lose a lot of weight – some of it will be fat, a lot of it will be water, and a dangerous amount will be muscle tissue. You'll lose weight quickly, but you'll slow your metabolism and gain fat more quickly once you go off the diet. Trust me on this. I've been there, done that.

The problem is that you've set the wrong goal. If you want to look better, have more energy and enjoy better health, the goal is not simply to “lose weight.” The goal is to improve your fitness level and body composition. That means losing fat, improving your aerobic capacity, training your strength and defending your muscle tissue. You can't do that with a no-carb diet. You will do it using the approach you'll learn on this website. Trust me on this one too. I know what it's like to feel fat, tired and helplessly out of shape. The whole point of this site is to help others avoid that, by sharing lessons that I had to learn the hard way.

also check out the last link in my signature. It's by Trainer Robin.

Look at your NET number. Eat enough so that number is between 1200 and 1370

If you Eat 800 OR LESS Calories your Body will go into Starvation Mode, so try to Eat 1200 every day at least!!!!

Trust me - I asked this question 2 weeks ago and was in the same boat. Yes you have to eat all those calories and even more if you exercise. It works - I've been dropping 1.5 lbs a week by eating 1200 cal a day. It seems silly but you have to eat to lose!

Good luck!