Caloric intake + exercise = extra calories needed?

Because MFP has already set you up with a calorie deficit (1250 calories). If you ate that and didn't do a lick of exercise, presumably, you would still lose a pound a week. Burning 1000 calories and eating 1250 calories would give you net calories of 250. I'm a fairly small female and I wouldn't be able to survive on that.

ok, So why can't I eat my 1250 calories (that would have me loose 1lb a week) as well as burn 1000 calories to help me loose more per week?

Because you would go into starvation mode. A person cannot survive on only 250 calories a day.

I would like to slim down, but not JUST slim down. I would like to know how to eat to stay slim and stay healthy. I want to do this the right way.

I suggest trying to hit your calorie goals every day, and paying close attention to your macros (carbs, protein, sugars, etc.) and try to hit those goals as well. You might want to aim for more protein than MFP actually recommends, and you can adjust those settings under the "goals" tab. If you don't feel comfortable messing around with all that just yet, though, I wouldn't worry about it. Just try to hit your goals every day, and you will lose weight and get in shape. Trying to meet your macro goals will help you stay healthy as well.

There is much debate around these parts about diet, whether it's okay to eat whatever you like as long as you are meeting your goals, or whether there are overall health benefits to particular diets ("clean" eating, raw foods, vegan, etc.) but for right now I'd stay mostly focused on just meeting your goals every day.

maybe there is a link that i could be pointed to, to help me understand this. I really don't want to take a college course to understand all this

I recommend hanging around the message boards and reading any of the topics that sound pertinent or interesting to you. You'll learn a lot of very useful information.

Your body needs nutricious food even, and especially when you are losing mass. If you don't consume enough, you'll start metabolizing your own muscles...which is NOT whet you want. Plus your metabolic rate can slow down, making it harder.to lose at all. Eat all or most of your earned calories.

The goal that MFP gives you does not include your bike riding if you set it to sedentary, and you would want to eat back those calories. That is my understanding, anyway. If I am wrong, please let me know.

You're right.

If you set up your profile as "sedentary" and a goal of 2 pounds a week, you are eating at a 1,000 calorie deficit daily below your estimated total daily energy expenditure. 1,000 calories * 7 days = 7,000 calories / 3,500 calories per pound = 2 pounds. As long as you aren't within 20 pounds or so of an ideal BMI, you should be able to do 1.5-2 pounds a week in a healthy manner as long as you are eating your calories wisely (getting your fat, protein, and carbs in reasonable balances).

Eating at a deficit burns a proportion of fat, muscle, and organs. The things that are needed most, and are used least, are burned. Therefore, exercising during weight loss is beneficial as it helps retain muscle and the body will tend to focus more on burning fat where energy is required.

However, as you start to make your weight loss faster (and how many of us don't want to do that?), the problem is that you are not feeding your body enough, and in particular enough protein, to sustain muscle. So no matter how much exercise you do, your body cannot repair the muscles you are using and will actually start cannibalizing them for protein (though it will focus on muscles you are not using first).

Muscle mass is NOT what you want your body to be losing. First, your body fat percentage does not improve, leading to the same kinds of health problems you'd have if you were very overweight (some people use the somewhat insulting term "skinny fat" to describe someone who is within a healthy BMI range but has a high body fat percentage). Second, losing muscle means your body is burning fewer calories on an ongoing basis, and you're REALLY going to struggle with those last few pounds.

If you are purely in this to lose weight and are in a hurry, then at least make sure you are meeting your protein requirements for a given day and take a multivitamin to make sure you are getting your vitamins and minerals. You're probably not going to be terribly happy with the results, but it's your body.

I bicycle 14 miles each way daily, and burn about 1,200 calories a day doing so. Wednesday really starts to suck if I don't force myself to eat most of those calories back on Monday and Tuesday, or if I eat empty junk to meet my calorie goal. If I focus on protein sources like nuts and lean meats to boost my calories up near my goal, I can get on the bike on Friday with a smile on my face and a song in my heart, happy to be avoiding burning another gallon of gasoline.

The goal that MFP gives you does not include your bike riding if you set it to sedentary, and you would want to eat back those calories. That is my understanding, anyway. If I am wrong, please let me know.

You're right.

If you set up your profile as "sedentary" and a goal of 2 pounds a week, you are eating at a 1,000 calorie deficit daily below your estimated total daily energy expenditure. 1,000 calories * 7 days = 7,000 calories / 3,500 calories per pound = 2 pounds. As long as you aren't within 20 pounds or so of an ideal BMI, you should be able to do 1.5-2 pounds a week in a healthy manner as long as you are eating your calories wisely (getting your fat, protein, and carbs in reasonable balances).

Eating at a deficit burns a proportion of fat, muscle, and organs. The things that are needed most, and are used least, are burned. Therefore, exercising during weight loss is beneficial as it helps retain muscle and the body will tend to focus more on burning fat where energy is required.

However, as you start to make your weight loss faster (and how many of us don't want to do that?), the problem is that you are not feeding your body enough, and in particular enough protein, to sustain muscle. So no matter how much exercise you do, your body cannot repair the muscles you are using and will actually start cannibalizing them for protein (though it will focus on muscles you are not using first).

Muscle mass is NOT what you want your body to be losing. First, your body fat percentage does not improve, leading to the same kinds of health problems you'd have if you were very overweight (some people use the somewhat insulting term "skinny fat" to describe someone who is within a healthy BMI range but has a high body fat percentage). Second, losing muscle means your body is burning fewer calories on an ongoing basis, and you're REALLY going to struggle with those last few pounds.

If you are purely in this to lose weight and are in a hurry, then at least make sure you are meeting your protein requirements for a given day and take a multivitamin to make sure you are getting your vitamins and minerals. You're probably not going to be terribly happy with the results, but it's your body.

I bicycle 14 miles each way daily, and burn about 1,200 calories a day doing so. Wednesday really starts to suck if I don't force myself to eat most of those calories back on Monday and Tuesday, or if I eat empty junk to meet my calorie goal. If I focus on protein sources like nuts and lean meats to boost my calories up near my goal, I can get on the bike on Friday with a smile on my face and a song in my heart, happy to be avoiding burning another gallon of gasoline.

This post is absolutely wonderful. I'm going to share it with my friends when they have questions about this topic.

Unless you get the exact same exercise every day, it seems to me that it makes more sense to track your exercise separately.