confused about the BMR in FitnessPal

ifisgood

Forget the details. I am on a journey using diet and exercise, and as I get further into the journey, I have been left confused by some of the elements I cannot manipulate on my page.
I set my vitals within my page as a sedentary desk worker with regular workouts, asking for a 2lb weekly loss. This gave me 1500kcal a day before exercise. I am progressing, but not a 2lb a week (closer to 1.5lb), even though I usually come in at least 2500 kcal under my weekly target kcal.
So I removed my goal, and Fitnesspal calculated 2040 kcal a day to maintain my current weight (if I ate that daily, I would be enormous in no time). I visited the FitnessPal website and input my details into a BMR calculated, resulting in a 1650kcal need. My smart scales support this.
So my question is, if I want to lose 2lb a week safely and make sure that I maintain my weight after reaching my goal, how do I get Fitnesspal to give me a natural target, and what is that real target?

Lietchi

BMR calculators (all calculators really) just give you a statistical estimate based on averages and individuals can diverge from those averages quite a bit (both over and under).

Real life data trumps any calculator.

So I would do this:
- add up your total food intake from the last 4 weeks
- to that number, add 3500 calories for each lb of weight you've lost over those 4 weeks (if you use a weight trend app, use your weight trend number)
- divide this number by 28: this is your average total calorie expenditure per day (including exercise)
- subtract 1000 from this to arrive at the number which should give you 2lbs of loss per week (if you stay at the same activity level)

Caveat:
- it's generally not recommended to go below 1500 calories (for men) or 1200 (for women) to ensure adequate nutrition. And to lose 0.5-1% of bodyweight per week, no more. Not eating enough/losing weight too fast carries health risks.
- you'll need to recalculate as you lose weight (smaller bodies require fewer calories)
- it might be worth checking how accurate your calorie counting is - those number sounds quite low for a man (but I don't know your age, height, weight or activity level)

Lietchi

Have you actually logged your food intake for 4 weeks while maintaining (at the same level of activity)?
Because when you say you would gain at the number you calculates based on my explanation, that would imply you need a deficit smaller than 3500 calories to lose 1lb of bodyfat.
3500 calories of deficit to lose 1lb of bodyfat is a commonly used number, I'm not expert enough to know how much this is true for everyone.

How much are you currently consuming per day, to lose 1.5lbs per week? Ideally you would consume 1500 + exercise calories.
But losing 1.5lbs per week as you are currently sounds pretty sensible at your current weight, if you aren't enormously lower than 1500+ exercise. (Not even sure where than number came from precisely, except MFP uses it as a minimum).

Not sure what your goal weight is, but we (MFP regulars) do generally recommend slowing it down a bit as we get closer to goal, it can make the transition to maintenance a bit easier, increasing calories gradually.

1 to 1.5lbs per week would be my personal choice.

ifisgood

I'm 62 with a fluctuation from 32 year olds attitude to fitness to a 65-year-olds love of pizza and beer on weekends.
Thank you for the calculation. It gave me a 2400 daily (caveat on recording everything I eat accurately daily). If I ate that, I would gain, not maintain.
For clarification, 186.5lbs 175cm desk job with five workouts 45mins and 6500 steps at pace at least 400 Garmin activity minutes per week.
Your calculation for a 2lb loss per week gave a 1394kcal per day, so I expect I will have to settle for 1.5lbs per week to stay above 1500kcal per day....so the next question is that if I am eating 1500kcal a day but burning 300kcal on exercising should I eat 1800kcal to make sure that I have cleared 1500kcal minimum?

AnnPT77

ifisgood wrote: »

I'm 62 with a fluctuation from 32 year olds attitude to fitness to a 65-year-olds love of pizza and beer on weekends.
Thank you for the calculation. It gave me a 2400 daily (caveat on recording everything I eat accurately daily). If I ate that, I would gain, not maintain.
For clarification, 186.5lbs 175cm desk job with five workouts 45mins and 6500 steps at pace at least 400 Garmin activity minutes per week.
Your calculation for a 2lb loss per week gave a 1394kcal per day, so I expect I will have to settle for 1.5lbs per week to stay above 1500kcal per day....so the next question is that if I am eating 1500kcal a day but burning 300kcal on exercising should I eat 1800kcal to make sure that I have cleared 1500kcal minimum?

As a general answer, yes, in MFP-world you would eat the exercise calories, too - a reasonable estimate of them. 300 calories sounds reasonable for 45 minutes of cardio at your size, for strength training maybe not so much.

I'm hoping you set your MFP activity level based on your life before intentional exercise, otherwise you can be double-counting exercise. You would probably be either sedentary or lightly active in MFP terms. (Lightly active depends on your home chores and such outside of exercise - 6500 steps would be lightly active for most people, but that's if daily life rather than exercise generates those steps.)

Not losing on 1800 total intake seems surprising, if 2400 is correct. Losing quite slowly on 1800 + 300 exercise calories seems somewhat plausible, especially if one were statistically unusual. That loss (maybe a bit over half a pound a week) could take weeks to show up on the scale through the confusion of normal daily multi-pound shifts in water retention and digestive contents (neither of which are body fat, obviously).

If I put your stats into an outside TDEE calculator at sedentary, I get estimates of total needs more around 2000 daily. I have to bump the activity level up there to include exercise most days in order to reach 2400.

I have to admit, I'm wondering how long you've been at this, to establish your personal estimates of gaining/losing/maintaining calories. (And yes, logging accuracy does matter - plus that's a surprisingly subtle skill. Most of us here have had forehead-slapping moments of realization that we'd overlooked or underlogged something(s)!)

The reason I ask about length of experience: I admit I'm a mysteriously good li'l ol' calorie burner, and one person's results tell us nothing about the next person, but I'd lose close to a pound a week if not more on a straight 1800 . . . and I'm 67, much smaller (5'5" (165cm), 130ish pounds), and 100% more female than you are. All of those factors would be likely to result in lower calorie needs. I'd lose very slowly even on 1800 + exercise.

Best wishes!

ifisgood

Hi Community
Thank you for these answers; they are instrumental and insightful. Since your answers, armed with the information you provided, I have moved forward, and if maths were as easy as losing weight, it would work, but either I am not recording, or I am not losing to the maths calculation. But I am continuing to lose, so I am happy. Thank you
Now I must figure out why my smart scales think I am losing 2/3 fat to 1/3 muscle mass even though I am strength training to ensure I don't lose muscle

AnnPT77

ifisgood wrote: »

Hi Community
Thank you for these answers; they are instrumental and insightful. Since your answers, armed with the information you provided, I have moved forward, and if maths were as easy as losing weight, it would work, but either I am not recording, or I am not losing to the maths calculation. But I am continuing to lose, so I am happy. Thank you
Now I must figure out why my smart scales think I am losing 2/3 fat to 1/3 muscle mass even though I am strength training to ensure I don't lose muscle

Simple: Smart scales aren't very accurate. At most, they might give a reasonable trend over many weeks, but the actual number is . . . hmm, very approximate at best, possibly pure fiction.

If you are avoiding fast weight loss (keeping it moderate, 0.5% of current weight weekly loss or less), getting plenty of protein and general good overall nutrition, and doing a good progressive strength training program faithfully, you're doing all that you can possibly do to avoid muscle loss.

Beyond that, why worry? I try not to stress about things I can't do anything to change. Once I'm doing all that I can, I strive to just settle in and do what needs to be done. Reaching a healthy weight is worth some effort.

nossmf

When you lose weight, part of that weight is almost guaranteed to be muscle, no matter how much exercise and protein intake are part of your routine.

When you intentionally gain weight in an effort to gain muscle, part of that weight is almost guaranteed to be body fat, no matter how much exercise and protein intake are part of your routine.

Bottom line, you probably are losing muscle as you lose weight. But the ratio is somewhat in our control. If you sit on your couch all day and seek to rapidly lose weight, the body will first look to supplement the "lack of calories" through bodyfat, but will also look to reduce the body's overall calorie needs by cutting down on the high-calorie-consumer tissue. Since the brain and internal organs are kinda important, these are the last to get hit, so the body instead reduces the amount of muscle on your body. Doing strength exercises helps tell the body it needs to retain as much muscle as possible to deal with this situation, and you're doing that.

The other side of that coin, as mentioned by @AnnPt77, is getting adequate protein. How much is adequate? You'll get a lot of different answers, but since you're close to the same bodyweight as me, I'll give you my personal results. I weigh 190 at the moment. On days I lift, I aim to take in at least 150g of protein; days I don't lift, I aim for a floor of 120g. (These numbers jive quite nicely with some website recommendations of 0.6-0.8g per pound of BW.) Some days I go well over (mmm, steak!) and some days I'm a bit under (mmm, sausage!). But in general I'm within 10g or so of these goals.

So the bad news is you WILL lose muscle as you lose weight, but you can limit the muscle loss through weight training AND high enough protein intake. Take a look at your current intake, and see if you are getting enough. You don't have to use my numbers, but if you're only bringing in 50-60g of protein per day then you definitely need to up it. This thread contains a lot of options for consuming protein.

Corina1143

I didn't see how much you're trying to lose, but at 5'9" 186 pounds, I doubt if it's a lot. 1.5 pounds a week sounds like a pretty good loss.