I've gotten quite a few emails from people who are still confused on how to calculate their BMR and figure out how many calories to burn and eat.
We'll use really simple examples...
One pound equals 3500 calories. No matter if you weight 500 lbs. or 150 lbs, 3500 calories burned will always be 1 lb.
Let's pretend my BMR is 1500. So to lose 1 lb. per week, I need to burn 500 calories per day over my BMR, so I want my net calories to be 1000 (Net is calories in (eaten) less calories out (exercise)).
To burn one pound, you can eat your daily 1500 calories and then use exercise to burn 3500 per week (500 calories per day).
Or you can eat fewer calories, like 1300 and burn 200 calories by exercise.
Or you can drop your calories to 1000 and not exercise (NOT RECOMMENDED! this will kill your metabolism unless you have a lot of extra weight.)
Here is the math for eat your BMR and use exercise to lose:
1500 calories eaten
- 500 calories burned by running
= 1000 calories net consumed daily, your body burns 1500, so your net loss is -500
-500 per day times 7 days per week = 3500, which is a pound!
Here is the math for eat less than BMR, and exercise:
1300 calories eaten
- 300 calories from running
= 1000 net calories consumed daily. Body burns 1500, so your net loss is also -500
Say you want to lose 1.5 lbs per week, you need to burn 5250 calories per week over BMR, which is 750 per day. Here's the math for that.
1300 calories consumed
-550 calories burned by exercise
= 750 net calories consumed daily, your body burns 1500, so you're at a net -750 calories lost.
750 daily x 7 days per week = 5250, or 1.5 lbs.
I know I'll confuse some people here, but you can, and should, switch up your days. You don't want to ALWAYS eat 1500 calories and ALWAYS burn 500 calories. Some days you can eat 1300 and burn 300, some days you can eat 1800 and burn 800... as long as you keep your net calories lost each week to 3500, you should lose weight.
Again, that's the math of it all. Your metabolism plays a factor, as does where your calories come from, how much water you drink, how much sodium you consume, and so on... that's why sometimes when you work really hard, you don't see a big loss on the scale. Depending on how active you are, you need to multiply your BMR by 1.1, 1.2, 1.3 or 1.4 depending on your activity. I would consider myself a 1.15, I don't sit ALL day, but I do sit at a desk often. I like to leave out the extra .15 in my BRM as wiggle room for calories over what I think or approximate, and assume that I'll come out even in the end.
But, in the end, if you're doing this the right way (which you are if you're in this challenge), you'll see a loss!