Questions about "eating back calories" - my two cents

I see people asking about their calorie levels a lot, whether to "eat back" calories worked off in exercise, that sort of thing. I want to make a couple of points that may be useful, and throw in some suggestions from my own education and experience.

FIRST:
MFP is a "feedback loop", which is something that gives you interactive information and feedback about your own actions, and which affects your subsequent behavior as a result (there's a whole article from an issue of Wired magazine earlier this year about feedback loops, by the way...) - that's what feedback loops do. The MFP feedback loop happens to use science-based calculations to drive its goals and calories and progress functions, and provides some very good guidelines, especially for people who really need basic guidance. The feedback loop, on the positive side, means that people are more likely to feel compelled to eat and exercise to meet a goal; the negative side may be that people will become hung up on the goal calorie number and be unhappy seeing "red", "going over" their goals, or otherwise be confused or disheartened by feedback that's actually inconsequential to their physical reality.

What MFP is NOT is a definitive point of reference, and cannot make up for basic understandings of health, nutrition and fitness. I am not a trainer or medical professional, but I have a lot of understanding of these things and want to give people a bit of basic reference that might help - please check it out further, but I'm pretty sure about a few basics.

First, we all probably know the rule of thumb that the body can't metabolize more than 2 pounds of fat in a week, and that it requires 7,000 calories to do this, or 3,500 per pound. This does not take into consideration the caloric requirements to support maintenance or slight building of muscle mass, either.

But it leaves us with the understanding that we should not consume less than 1,000 calories under our maintenance requirement in a day - I need about 1900 - 2100 calories a day to maintain my weight at a variable basic activity level (not including vigorous exercise, but including non-sedentary activity), so I should not drop below 900 - 1100 calories, ever, in a day, if I were trying to lose 2 pounds of fat a week. However, this should be a net figure: most fitness professionals do not suggest that level of calorie deficit in food - it's almost unsustainable and hard to get proper nourishment.

So we're also assuming we will target a caloric remainder through exercise to get to that 1.5 to 2 pound weekly fat burn. This is the point at which our MFP settings and feedback may become confusing: if I set my weight loss goal to 2 pounds weekly, MFP is telling me to eat 1100 calories a day, then giving me more when I exercise. Because this is the FAR end of fat metabolism, I DEFINITELY SHOULD eat those calories back. However, if weight loss speed is set to 1.5 pounds, or especially less than that, per week, it is not always going to be necessary to "eat back" calories.

Also, if you are significantly overweight, MFP or any similar calculator is going to skew things... let's say you're a somewhat active, 5'7" woman weighing 250 pounds: MFP will tell you your maintenance calories are very high, maybe around 2700 calories a day - this makes sense - you've had to be overeating to reach this point, and will have to continue to overeat a bit to maintain it (in most cases). Therefore, your 500-cals/day deficit, while helpful in your quest to lose a pound a week, is different than that of a thinner person's - if you're being told that 2200 calories a day is a deficit for you, you have plenty of room to eat less, and plenty of room not to eat back calories worked off. So if you're weaning yourself off eating too much, this can be helpful, but in the long term is possibly not the best guide to follow.

I suggest a few steps to get to some solid figures you can write down and refer to, instead of (in addition to) MFP feedback.

First, quickly use MFP to learn your base line maintenance level intake - be sure to be honest about your normal (non-exercise) physical activity level. Change your goals to weight maintenance, set all your current measurements correctly, and see what it tells you your maintenance calories are (write this down). Now you can change your goals back to whatever weight loss speed you've been aiming for.

Next, if you have more than 20 or 30 pounds to lose (if taller, more than 30 or 40 - at this point this only makes about 100 cals of difference to my situation, for instance), use another on-line calculator such as http://www.freedieting.com/tools/calorie_calculator.htm to find out the maintenance caloric requirement for a person of your same age, height and gender at your (REALISTIC! This only works if your goal is REALISTIC...) GOAL WEIGHT.

For many women, 1800 - 2100 cals/day is going to be a sensible MAINTENANCE intake for goal weight WITH 5 days of exercise per week (older and smaller people will, sadly, need less food, but hey, it's still not such a bad deal - a 65-year-old 5'4" woman working out 5 days a week needs about 1700 cals to maintain 140 pounds - that's still a nice full day of food!).

So, you can use one of these as a starting point - either your actual maintenance level (for people with maybe less than 30 pounds to lose) or your goal-weight maintenance level (for people with 50 or more pounds to lose).

If you're very overweight, now you can check if your goal-weight calorie level is roughly in the ballpark of what you are being instructed by computer programs to consume to reach a deficit - if GOAL CALORIES are LESS than CURRENT DEFICIT CALORIES, you may want to start revising your eating habits to consume less - first, it's safe and you'll probably lose weight faster, and second, you'll become more comfortable with what that feels like, and possibly find it easier to maintain that once you are at or near your goal.

Now that you know your maintenance level, factor in a realistic deficit - probably no more than 500 calories - that you can live with eating daily and feeling strong on. This is where it gets simple: I need about 2100 cals to maintain my weight; I need about 1600 to burn a pound of fat a week.

Try not to go too far BELOW a deficit of 500 - again, if you are eating nearer a 1000-cal deficit, you have run out of room for fueling workouts, and are closer to working against your fitness and weight loss goals if your body begins to slow down to conserve energy.

On the other hand, at this level of deficit, you should have enough leeway 1) to work out up to a 400 - 500 calorie burn without needing to "eat back" (though you should always refuel after a workout, and pay attention to your energy levels), especially since you shouldn't be working out quite that hard every single day, and 2) to eat an extra 100 - 200 calories every now and then (couple days a week) or even an "extra" 500 once every couple of weeks without "blowing your diet" - I'll still be killing it on a 1700 cal day, for instance.

So I strongly suggest getting an idea of a sensible daily target number in mind - use MFP to do so by choosing the pound-a-week loss goal - and aiming to eat that pretty much every day, without any thought of "eating back" your workout calories (unless you're starving / super athletic / etc.), and only with concern as to what the final daily intake is, not to whether MFP says you're "under" or "over".

ONE BIG BENEFIT of this approach - setting a 1-pound/week goal, but working out on top of this instead of as part of it (adding a 300-cal burn to a 500-cal food deficit day for a total deficit of 800) is likely to give you the psychological boost of outperforming your goal and losing faster - setting a 2-pound goal is likely to have the opposite effect.

Stay motivated with MFP, but use it as a tool, not a just a feedback loop you react to mechanically, without your own knowledge.