Why are calorie consumption numbers so different?

hcdo

Entering the same information for my age, weight, height, exercise level, etc., MFP says I need to eat 1,200 calories to lose a pound a week, TDEE says I should be eating 1456, and the Institute of Medicine's "estimated calorie requirements" say that I should be eating around 2,000 calories a day. I don't know which to believe.... How do you decide?

DemoraFairy

2,000 is just a general number, of course it won't be right for everyone. A 6ft athlete is going to require a lot more calories than a 5ft office worker. Go with the one tailored to you (the MFP or TDEE one).

malibu927

The difference between MFP's calories and TDEE is that TDEE already includes exercise calories, whereas MFP's do not (which is why you log and eat a part of them back). The other number is probably your actual TDEE, as it's about 500 (20%) above the 1456.

hcdo

Thanks! The difference between MFP and TDEE is almost 300 calories, though. How do I decide which would be best?

DemoraFairy

What are your stats? (Age, height, weight, activity level)

When it says your TDEE is 1456, is that the amount you need to eat to lose weight, or how much you burn on an average day?

TimothyFish

2,000 is a nice round number to give people an idea of what they should be eating. Men will tend to need more than that to maintain their weight and women will tend to need less than that. TDEE is not how much you need in order to lose weight but is a number indicating how many calories you burn during a day. 1200 is probably closer, but it may not be correct for losing weight at one pound per week, because 1200 is the lower limit for MFP. You may be so light that it won't give you the calories for a one pound weight loss. If your TDEE is 1456, a one pound weight loss would be 956 calories per day.

3dogsrunning

TimothyFish wrote: »

2,000 is a nice round number to give people an idea of what they should be eating. Men will tend to need more than that to maintain their weight and women will tend to need less than that. TDEE is not how much you need in order to lose weight but is a number indicating how many calories you burn during a day. 1200 is probably closer, but it may not be correct for losing weight at one pound per week, because 1200 is the lower limit for MFP. You may be so light that it won't give you the calories for a one pound weight loss. If your TDEE is 1456, a one pound weight loss would be 956 calories per day.

TDEE of 1456 would be for someone who is very small and light and not active at all. Plus 1 lb a week would be too high of a goal.

Op - whe comparing numbers you need to account for whether they include exercise or not. As someone mentioned above, MFP does not factor in exercise. Other calculators, like a TDEE one, do. If done correctly, both of these numbers should average out over the week once you include exercise.

Also make sure you are factoring in the same weight loss goal. 2lbs a week is 1000 calories less than your maintainance. 1 lb a week would be 500. Some calculators go by a percentage. 20% is often recommended. If you are starting at a 2000 calorie TDEE, a 20 % deficit would be around 1 lb a week. So you can't compare that to a 2lb a week goal on MFp.


If you want suggestions, what are your stats, height, weight and activity. What are you doig for exercise?

hcdo

Thanks, I forgot to account for the exercise calories I earn back on MFP. This makes MFP cals and TDEE close to the same. The only weight loss goal I put in was for MFP; the others just gave me numbers based on my stats. I'm 40, 5' 3', a little over 130, and am doing a fairly light amount of exercise after a loooooong hiatus. (FYI, starting over sucks.) I'm not even necessarily trying to lose that much weight, more just trying to lose the fat that has snuck up on my body over the years and replace it with muscle. It's very, very slow progress and very discouraging to see such little change in my body. I used to be a runner, and in the past could at least maintain my weight, but I'm now trying to do more HIIT-type workouts in the hopes that it will give me better results than just basic maintenance. Also, I'm finally starting to get over the "I exercise so I can eat whatever I want" mindset, which is why I'm trying to focus more on caloric intake. 1,200 seems a bit restrictive so I thought I'd check with everyone. Thanks for all the info!

cwolfman13

hcdo wrote: »

Entering the same information for my age, weight, height, exercise level, etc., MFP says I need to eat 1,200 calories to lose a pound a week, TDEE says I should be eating 1456, and the Institute of Medicine's "estimated calorie requirements" say that I should be eating around 2,000 calories a day. I don't know which to believe.... How do you decide?

MFP doesn't include exercise in your activity level...TDEE does. With MFP you account for exercise activity after the fact when you log it...so 250ish more calories for exercise on top of your 1200 alloted would put you right there...with TDEE, an estimate of your exercise calories are already included. I would assume the Institute of Medicine's estimate would be to maintain.

YalithKBK

Also, once you pick a number, see how it goes. These numbers are never absolutes, just guidelines. Even two people the same age/weight/height eating the same number of calories could have very different results. Pick one, try it for a month or two. If your weight doesn't do what you want, adjust accordingly.

kpw818

Hi there!

I struggled with this as well. As I am doing maintenance/more watching for nutrients (MFP just happens to be awesome to track), I was confused on the low, low numbers. I'm 5'2 and about 113. If I never did anything 1200-1400 would probably be correct for me to maintain and lose. However, I am fairly active. I run 4 days a week (3/6/3/12 for approx mileage) and I strength train on Tue/Thur. I was trying to do the eat back exercise to maintain and that just didn't work. So, I looked at a couple different calculators and did a formula I found here, and then took a nice round average of 1800.

1800 is high for no activity days, but as you can see, I only have one of those. I feel this number is still low when I figure in exercise, but it was one I felt comfortable starting with as I was also naturally eating around that amount every day. I'm watching to make sure I'm not losing weight, because I don't really need to, and planning to up a bit if needed.

tl;dr you can review different calculators, all based on different formulas, but in the end you will probably need to just monitor and see what really works for you.

StaciMarie1974

TDEE considers exercise and MFP expects you to add that in. So if you're averaging 250 calories a day exercise, those 2 balance out.

Estimated calorie requirements are not based on you & your activity/size. But if you mean they recommend 2000 to maintain, it falls right in line with the others. IF 2000 to lose 1 pound a week, then you may be smaller than the 'average' they used.

hcdo wrote: »

Entering the same information for my age, weight, height, exercise level, etc., MFP says I need to eat 1,200 calories to lose a pound a week, TDEE says I should be eating 1456, and the Institute of Medicine's "estimated calorie requirements" say that I should be eating around 2,000 calories a day. I don't know which to believe.... How do you decide?