BMR super low - How to lose weight?!


My BMR on MyFitnessPal was 1500 and I wanted to lose the most I can i.e. 1kg a week as per the minimum on the app. So my calorie intake was 1200. I barely lost 2kg in 6 months.

However, I now have the latest smartwatch that calculates a live BMR depending on my body composition, movement, heart rate, etc. I.e. more accurate than an online calculator. Turns out my BMR is 1300!!!!!
So 1200 calories is not low enough for decent weight loss!

I've now set my calorie intake to 1100 but I doubt that's enough to keep me sane, as 1200 was already low enough I was barely eating 2 meals a day.

Any tips?

I'm 37yo, 82kg and 155cm.


  • spiriteagle99
    spiriteagle99 Posts: 3,680 Member
    I wouldn't eat less than 1200 calories, so you would do better to get more active. Not just deliberate exercise, but movement throughout the day. If you burn more, then you can eat more. You need to get sufficient nutrition, and that is impossible if you cut your calories too much.

    Were you actually weighing every bite you ate? If you were not losing while eating 1200 calories, usually it's a question of not being exact on your measurements so you are actually eating more than you thought you were. It is very easy to do.
  • Theo166
    Theo166 Posts: 2,564 Member
    Instead of eating less, increase your activity, which gives additional health benefits. Do daily walks as an easy way to increase calories out.
  • nooshi713
    nooshi713 Posts: 4,877 Member
    My BMR is 1250. It is tough being short. I feel your pain.
  • sheahughes
    sheahughes Posts: 133 Member
    I have a couple questions (and I am not an expert by any means)...
    Were you logging and eating back at least some of your exercise calories?
    When you say BMR, do you mean Base Metabolic Rate as compared to TDEE (Total Daily Energy Expenditure) from a TDEE calculator like sailrabbit or are you perhaps confusing the calorie intake figure MFP gives you with BMR? The calories MFP recommends you eat do not include purposeful exercise, you are expected to log and eat those too.
    Do you have your activity level set too low? I have seen recommendations that Sedentary would apply to anyone who gets less than 3000 steps per day.
    Are you weighing your food and selecting appropriate entries from the database? Are you weighing/measuring everything, condiments, cooking fats/oils etc?
    What is your device, how does it measure movement and is it correctly set up?
    1200 calories would be the absolute minimum you should eat for a healthy body. Being petite like we are can be very difficult if we are not purposefully increasing our movement throughout the day or exercising.
  • Amandy60
    Amandy60 Posts: 3 Member
    Thanks for all the comments everyone. I agree.
    1. No I'm not weighing or calculating exact calories. At times, I'd scan the barcode or if it's a home cooked meal, I would choose an appropriate one from the MFP inventory.
    2. Yes, I am mostly sedentary with a desk job. But when I exercise, walk, treadmill, dancing, it links in with my Polar Beat device or Samsung Health app linked to my Samsung Galaxy Classic 4 Watch.
    3. The Watch calculated my BMR, not TDEE. MFP made a calculation based on weight, height and lifestyle which I chose as sedentary.
    4. Are all calories equal? I don't know. I don't eat chocolate, might snack on popcorn once a week and despise takeaway food. So I'm not eating crap. Probably just not moving enough.

    In conclusion, I need to workout more, not eat less.

    I know it does seem like a simple mathematical analysis of input and output, but having PCOS doesn't help as my doctor said it is twice as hard for me to lose weight than a non-PCOSer. 😞
  • AnnPT77
    AnnPT77 Posts: 32,382 Member
    edited November 2021
    I agree that not everyone needs to do the precision food logging/calorie counting in order to succeed . . . but that it's a good diagnostic to do it for at least a few weeks, to find out what the issue may be.

    I'd add this: Using database entries for other people's fully prepared foods (lasagna, meatloaf, ham sandwich, whatever) on a "per meal" basis . . . that's one of the least likely to be even remotely accurate methods. Even a tablespoon of oil/butter difference is going to be a calorie swing of 120 calories for the meal, let alone portion sizes and whatnot.

    Also, I'd point out that exercise isn't the only way to move more. It's possible to bump up daily life calories, too, and that can quite easily amount to a couple of hundred calories daily. (Researchers see that magnitude of difference between fidgety people vs. non-fidgety ones. I'm not necessarily suggesting you try to fidget, just using that to point out how meaningful small changes can be.)

    There's a thread about that here, and it links to some other similar threads IIRC:

    Not all those ideas will work in your life, but some might. The calories form those don't add up quickly, because it's about small habits changes. However, many of us when overweight have developed long-term habits of subtle inactivity. Working at changing that can help create a "bias toward movement" in daily habits that can not only help us reach a healthy weight, but stay there. There are folks here maintaining on calories similar to what they ate when much more overweight, just because they've become so much more spritely and energetic overall.

    ETA: My fitness tracker thinks my BMR/RMR is 1339 - I'm 5'5", mid-120s pounds, turn age 66 tomorrow, sedentary outside of intentional exercise, and severely hypothyroid besides (though properly medicated). My maintenance calorie requirement, before including exercise, is close to 2000, as validated by 7+ years of fairly precise logging so far. Some of that gap, I suspect, is from incorrect BMR estimate, some of it is body composition (I'm not a body builder, but somewhat more muscular than average for my demographic), some of it is daily life movement. A low BMR estimate is not doom.
  • mom22dogs
    mom22dogs Posts: 470 Member
    Your BMR doesn't matter. You need to eat more than your BMR. Your BMR is the calories you burn being in a coma, not moving. That is not the amount of calories you burn. Sounds like you aren't tracking calories correctly. As others have said, track correctly first to see if that is the issue.
  • sijomial
    sijomial Posts: 19,811 Member
    FYI - apart from being of very little use apart from just a part of your overall needs the BMR estimate from your watch is using the same metrics as any old BMR estimate you might get.
    You don't know your body composition, you movement is nothing to do with BMR at all as it's a total rest estimate and heartrate only has loosest connection to calorie expenditure and again as soon as you aren't at rest that's not BMR.

    It's not using any special data just because it's a wearable device, it's just given you a different number and with no guarantee it's any closer to reality.

    If you want a bigger food allowance you need to move more, both general activity and exercise.
  • debrag12
    debrag12 Posts: 1,071 Member
    your deficit comes from your TDEE not your BMR. On MFP is generally goal + exercise/increase in activity level.
  • russellholtslander1

    A better option is to use a TDEE calculator.

    This will let you choose activity level, body fat %, and give you a caloric level to maintain. Total Daily Energy Expenditure. Then cut 500 calories a day from that number, to lose 1 lb. a week. See what happens. I think you will be surprised to lose faster, on more calories.

    As fat % drops, your TDEE goes UP.. more muscle burns more calories..

    So if you do moderate exercise, and have 35% fat.. your TDEE is 2350.. so 1,850 calories should help you lose 1 lb. a week... 1600 calories helps you lose 1.5.

    I would stay ABOVE 1500 calories a day. Try the TDEE - 500 calories, and see how you do in the next 2 weeks.. then adjust accordingly.
  • westrich20940
    westrich20940 Posts: 879 Member
    OK...the only reason that your BMR is important here is that you want to eat MORE than your BMR. Your BMR is what your body would need to survive if you were in a coma.

    I don't know how much you are wanting to lose but in a lot of circumstances....losing 2lbs/week isn't going to be ideal. I know that when people want to lose weight they want to do it quickly - the only ways to do that are unhealthy. So just don't.

    Your TDEE (if you are a female) is probably around 1700/day. Your BMR is 13/1400......these are all just ESTIMATES though.

    So you want to set your calorie goal to something less than your TDEE, but more than your BMR. If I were you, I'd shoot to eat 1500 cals per day. Since you have 'sedentary' as your lifestyle then you can also incorporate some workouts into that routine if you would like to try to extend your caloric deficit a bit. Do not go overboard and I'd suggest that if you burn a LOT of calories through cardio workouts you eat back some or all of those calories.

    Also - if you are short, or the room you have to work with between your BMR and TDEE is tight....your weight loss will HAVE to be slow. And it becomes increasingly important to log properly when it comes to what you've eaten and what you've burned.

    If you just choose a similar dish from someone else's homemade entry in the database it could be SIGNIFICANTLY different than what you actually ate. I don't agree with being obsessive about calorie counting but being within +/- a couple hundred is important - generally speaking (I'm not talking about a day or meal every once in a while where you go way over or something).