This topic comes up time and time again.

In simple terms and with arbitrary numbers as an example, here is how MFP interacts with you, and this will answer the question:

MFP: How much weight do you want to lose per week?
You: 1lb.
MFP: Okay, if you'd like to lose 1lb per week, you need to eat 1800 calories per day without exercise.
You: Nice. I'll do that.

So you do it, but then you decide

"Hey, I really should exercise because it's healthy"

You: Hey MFP, I just ran to Wal-Mart.
MFP: That's great, but you burned 600 calories on your run! I told you to eat 1800 to lose 1lb/week without exercise. Since you exercised, I'd like you to eat 2400 calories (1800+600) so we stay at our agreed goal.


Now a consideration -- MFP will often overstate the burn calories for exercise.

Consequently, it is typically in the users best interest to eat back a portion of exercise calories.



But won't I lose weight faster by not eating back my calories?

You'll create a larger deficit, but you'll also risk losing lean mass, and anecdotal evidence would suggest that you'll also risk long term failure.

Slow and steady wins the race.

A less often asked question about eating exercise calories. Is there a conflict between the lifestyle activity setting and exercise calories?

For example, Webmd lists the following definitions for activity settings:

Sedentary: little or no exercise
Lightly Active: light exercise or sports 1-3 days/week
Moderately Active: moderate exercise or sports 3-5 days/week
Very Active: hard exercise or sports 6-7 days/week
Extremely Active: very hard daily exercise or sports; or physical job or 2X day training

In other words, if I adjust my activity levels do I even need to log exercise or worry about eating exercise calories?

I do wonder about the accuracy of the concept of "eat your exercise calories" based on size. For example, a person who begins close to 300 calories and needs to lose half of their body weight seems to be able to lose better (or just as well as anyone else) with higher deficits than MFP estimates. But the closer a person is to goal, the more important it becomes to eat those exercise calories. This seems to be frequently overlooked. Perhaps because it goes back to what you mentioned about losing less and less per week as you reach your goal? I'm suggesting that it becomes more important to increase your calories the smaller you get, but that larger "dieters" may be perfectly okay to have larger net deficits initially.

Discussion?