confused about calories vs exercise

The math in a nutshell:

MFP uses the NEAT (non-exercise activity thermogenesis) method to calculate your goals. So it's saying, okay, this person burns calories merely by being alive, going to work, brushing her teeth, running errands, sitting at a desk, breathing, basically doing everything that isn't exercise. Let's take that number of calories and subtract a deficit from that (500 calories/day to lose 1lb/week, for instance). So if she doesn't do any other exercise or workouts beyond her normal daily routine, she should lose 1lb/week eating at the calorie goal we give her.

Now, let's say you go to the gym and work out for an hour and burn 250 calories. In order to maintain that 500 calorie daily deficit, MFP would expect you to eat back those 250 exercise calories. If you don't, now you've created a 750-calorie deficit (in this example), which is likely too steep for you.

The actual numbers in this example aren't relevant. The relevance is the way this works. So you'd enter your height, weight, age, and daily activity level excluding exercise, and that gives you a net calorie goal. If you exercise, you should eat back those calories in order to maintain the same deficit. That's how it's designed to work.

Two caveats, though:

1. If you go into MFP's exercise database and log your exercise, it will estimate how many calories you've burned doing it. YMMV but many people find that MFP's database vastly overestimates calorie burns for cardio exercise. You may want to manually lower the burn estimate, or else just decide to eat back, say, 50% or 75% of your exercise calories, not 100%. Because you can quickly erase your deficit if you're constantly overestimating exercise burns and eating back too many calories.

2. If MFP gave you 1200 calories as a net goal, that's the minimum it assigns to women. Unless you're very small, short and inactive, it's probably too low for you. You likely were given 1200 calories because when MFP asked you how quickly you wanted to lose weight, you picked the maximum 2lbs/week. That's not really realistic for most people unless they're very obese, and usually big, tall and male. For most women trying to lose moderate amounts of weight, 1lb/week is going to be the maximum recommended, and by the time you get down to those last 10-15 lbs, you should be looking more at 0.5 lbs/week. There are many reasons for this, but mathematically it comes down to creating a reasonable 15-20% calorie deficit and still getting your nutrition in and feeling full. If your maintenance calories aren't that high, it's simply not realistic to create and sustain an 1000-calorie daily deficit unless you're starting from a really high number. Try editing your goal to reflect the slower pace, and MFP should give you a higher net calorie goal.

Hope this helps!

cwolfman13 wrote: »

Just from a purely common sense standpoint, why do you think MFP would give you those calories and increase your goal if you weren't supposed to eat them back? Do you think MFP is just trying to trick you?

Have you read the stickies...they pretty much explain how this tool works.

It is confusing at first. I know a lot of people don't intuitively understand the need to eat back exercise calories. After all, the thought process usually goes, "I'm here to lose weight, so why wouldn't I exercise more and lose faster?" It's a bit complicated if you've never thought of it in terms of what a reasonable deficit is before.

Echoing the advice to read the sticky posts. Lots of good info there.

RolemodelmomT wrote: »

Really helpful info...one question. where are the sticky posts??

They're the announcement posts at the top of each of the forums, like this one or the "getting started" forum.