Article in SHAPE magazine

Everyone is different, for one. I do best when I eat all my exercise calories -- but I use a HRM and then subtract my BMR from it so I'm getting the most accurate calorie burn.

If you're guesstimating how many calories you're burning, I would say eat half 'cause you could be overestimating what you're burning. Just play with it and if it works, fine! If not, try something else.

I never believe anything until I research it for myself.

Basically, it's all just advice. The only absolute immutable law of losing weight is to eat less calories than you burn. Everything else is someone's opinion on the best way to do it.

Personally, I had a set number of calories per day with daily protein, carb and fat goals and I ate to that and didn't even put my exercise into MFP. As my workouts increased past the typical workout, my doctor had me up certain goals, but I never directly looked at calories burned in exercise and directly tried to replace them. That worked for me while losing.

Now that I'm maintaining, I do enter the exercise calories but I don't try to eat them all every day. I just try to keep my net calories to my maintenance level on average. So some days I go over and some days I go under but it all evens out in the end.

IME most people end up over-estimating the calories burned in exercise and underestimating both what they can eat and what their daily calories are. Sites like MFP were telling me I should be losing 2 lb. a week back when I was losing 1 because they over-estimated my calories. They also told me I was burning a lot more in exercise than my HRM said I burned.

If I just blindly followed them, I would never have lost weight because I would have been eating too much.

By BMR do you mean your resting heart rate?

BMR = Basic/Basal Metabolic Rate = the number of calories you burn just existing. So, if you were in a coma or spent the entire day in bed without moving
RMR = Resting Metabolic Rate = similar but it's the amount you burn just sitting. So, if you watched tv all day sitting on the couch

These are multiplied by an activity level to give an estimate of how many calories you burn not counting exercise - your maintenance calories, so to speak. If you add in your exercise calories, you get your TDEE = Total Daily Energy Expenditure.

TDEE = (BMR * activity level) + exercise calories

If you use RMR, the activity level multipliers are smaller than if you use BMR. RMR is often used because it's easier to measure. There is a machine you breathe into for 10 min. that measures how much CO2 you exhale vs. O2 you breathe in and that gives you your RMR. Some scales estimate your BMR based on their estimate of your body fat. These may or may not be more accurate than a formula such as MFP uses since they are using your body fat measure. But, if they are very far off on the body fat, the BMR won't be correct either.

So, for example, my formula is:

BMR = 1250
Activity level = lightly active (1.375)
Exercise: average 300 cal. a day

TDEE = 1250 * 1.375 + 300 = 2018.75