Confused about BMR, eating back calories, deficits, etc...

When you create your MFP account, it asks your for your daily activity without exercise and creates and daily calorie limit based on that info (with your age and weight). So any exercise you put on top of it is extra and now the daily output has increased, which means you're 'allowed' more calories. So if you continue to hit your MFP daily limit, you are STILL going to be at a deficit, because MFP takes your desired weight loss into account when it creates that info for you.

Think of it this way: you hire a contractor to remodel your kitchen and he gives you a price of 2000. If you change your mind one day and decide you ALSO want him to remodel your bathroom, the price is going to go up. Same thing for your body. Your body is going to cost X amount of calories to run every day doing your routine activities. Once you add more activity to your day, the 'price' goes up and now you owe your body more calories.

If you feel full and still have calories left, just try to aim for 1200 NET. Calorie dense foods will help you hit your goal if you're still too low: nuts and nut butters, avocados, oats, etc.

MFP sets you at a deficit whether you exercise or not. If you exercise but don't eat those calories back you are creating a double deficit....and probably not consuming enough to fuel your body. Over a day or so....not a big deal. Over a longer time though, you could cause your metabolism to slow.....making losing at all harder, and perhaps causing other problems too. So eat those calories! Your body needs fuel to run well, even when you're losing.

Don't eat your calories back if you can help it. If you have fat on your body that you are trying to use, why would you deliberately eat more? If you are starving because of your workout and absolutely must then thats fine, but its there if you need it, not a requirement.

Personally, I eat my exercise calories back, or at least enough to net above my BMR, as I said above. If your goal is only 1200 calories a day (which is considered the bare MINIMUM daily intake for most women), then I highly recommend eating your exercise calories back, otherwise you end up with a net below 1200, and likely well below your BMR. You might see some quick weight loss for a time, but will likely end up stalling, feeling hungry, grouchy, and tired, and without enough energy to fuel your workouts.

You've probably seen the term "starvation mode" thrown around on the boards - you're not going to starve eating that little, but if you don't fuel your body properly, it will eventually slow your metabolism to match your intake. Not eating enough gives your body a reason to store fat - it's not getting enough fuel, so it holds onto whatever it can, stalling your progress and making you very frustrated. Been there, done that!

Some on the boards will tell you they never eat theirs back, others say eat a portion of them - everyone's different and you kind of have to find what works best for you. But dropping below 1200 with your net calories is generally not enough food. Like I said in my previous post - find your BMR and your TDEE, follow the guidelines in the link I posted - stay in between those numbers and you will see results!