Is MFP dangerously underestimating my calorie needs?

FitToFatToFitAgain
FitToFatToFitAgain Posts: 14 Member
in Health and Weight Loss
Hello! I’m a young, short woman who has lost a considerable amount of weight in a short amount of time. It went slower when I was mostly inactive, but now I’m going to the gym and I’m scared I’m undereating.

Like, MFP has my calories to lose 0.5kg (1lbs I think) a week at 1200. I’ve been eating around 1300 since losing 0.2kg a week requires about 1400 calories. I’m a student so I’m not that active daily, do strength training 3-4 times a week for 45 minutes eating back an estimated half of my calories burned and have a relatively normal to slow metabolism.

This week was my birthday week. On multiple days I skipped the gym and went way over my 1400 calories and even my supposed maintenance (1700 calories a day). I checked today and from last week to this week (weighed at the same time of day, in the same clothes, on an empty stomach), I’ve lost 1.1kg.

Is this healthy? I’m pretty accurate when tracking (measuring my food and all) so I’m not grossly underestimating my caloric intake. Is MFP calculations making me eat much less than I should?

Replies

  • NovusDies
    NovusDies Posts: 8,940 Member
    What is a short amount of time?

    At the beginning of weight loss it is not unusual to lose some water weight. You may also be seeing water weight changes because of your TOM.

    Even still it is very possible that you are not eating enough. It is hard for some people to properly gauge their activity initially. It takes about 6 weeks for a woman to get a proper read on a rate of loss.

    I would not put too much thought into eating more for your birthday and it resulting in loss. The bathroom scale is actually only a good measure of results over a month or more. Day to day and even weekly there are other factors involved. Read this:

    https://physiqonomics.com/the-weird-and-highly-annoying-world-of-scale-weight-and-fluctuations/

    There is no real danger if this has been going on for a short time.

    Are you feeling fatigued?
  • kshama2001
    kshama2001 Posts: 28,052 Member
    Few questions for you. Please answer all of them:
    1. Has it been at least 5 weeks? Throw out the loss from the first week. How many pounds did you lose the next 4 weeks?
    2. How many pound should you have lost?
    3. If you had eaten 100% of your exercise calories, how many extra calories would that be?

    FYI, many women retain water when we ovulate and/or premenstrually, and have a corresponding drop afterwards.
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    I’m anemic so I always feel fatigued haha.

    I’ve lost over 30 pounds in 4 months with 2 of those months having no exercise other than walking.

    Thank you for your reply! I’ll definitely reas the article you’ve shared!
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    One thing is you underestimating the calories you’ve consumed and another is MFP’s suggestion of how many calories you should consume. I went to see a dietician and she said that even at my being a 5ft nothing woman I should be eating more than 1200 calories since I’m not completely immobile all day everyday even though MFP tells me it would have me at a healthy rate of weight loss 🤷‍♀️
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    FitToFatToFitAgain wrote: »
    One thing is you underestimating the calories you’ve consumed and another is MFP’s suggestion of how many calories you should consume. I went to see a dietician and she said that even at my being a 5ft nothing woman I should be eating more than 1200 calories since I’m not completely immobile all day everyday even though MFP tells me it would have me at a healthy rate of weight loss 🤷‍♀️

    What is your current weight? 1 pound a week may not be a realistic goal for you. MFP gives you a goal that is based on your desired rate of loss. For those of us who don't have a lot to lose, 1,200 will often show up with a goal that is too aggressive because MFP can't go any lower than that. On top of that, MFP is expecting for you to eat *all* your exercise calories, so if you're intentionally not doing that it isn't surprising that you may not be eating enough.
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    1. It has been pretty much 16 weeks from the start but these last two months I’ve been going over my “maintenance” a lot and still keep losing weight at a pretty hefty pace.
    2. I should have lost 2.8kg or less - since I’ve been going over often - but I’ve lost 6.3lg
    3. About 150 extra calories? I’m estimating how many I’ve burned so it’s not exact (I estimate each 1hr gym session to be 300 cals burned 3-4x a week)

    My hormones are all out of whack so I’m not sure how accurate that is for my body but hopefully the doctor will be able to get them fixed so I’ll keep that in mind for the future!
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    janejellyroll wrote: »
    FitToFatToFitAgain wrote: »
    One thing is you underestimating the calories you’ve consumed and another is MFP’s suggestion of how many calories you should consume. I went to see a dietician and she said that even at my being a 5ft nothing woman I should be eating more than 1200 calories since I’m not completely immobile all day everyday even though MFP tells me it would have me at a healthy rate of weight loss 🤷‍♀️

    What is your current weight? 1 pound a week may not be a realistic goal for you. MFP gives you a goal that is based on your desired rate of loss. For those of us who don't have a lot to lose, 1,200 will often show up with a goal that is too aggressive because MFP can't go any lower than that. On top of that, MFP is expecting for you to eat *all* your exercise calories, so if you're intentionally not doing that it isn't surprising that you may not be eating enough.

    I’ve been eating half since I’ve read that most people tend to over estimate calories burned, so eating half of them back will reduce the chances of eating more than you burned but that could totally be the case!

    Right now I’m 51.7 so pretty much 52kgs (115 pounds I think) and I’m 5ft tall. I started off at 65kg eating 1200 a day and eating back all of my “exercise calories” AKA me walking at around mid November so 4 months back. I don’t really have a goal weight, just kind of looking at my body and seeing where it’s at. I have a fairly muscular build naturally so I usually weigh more than others even if at a lower body fat which is why I don’t use BMI.

  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    Also, recently I’ve been going way over my “maintenance” consistently and I’m still losing weight so I just want to make sure I’m losing weight in a healthy way :)
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    janejellyroll wrote: »
    FitToFatToFitAgain wrote: »
    1. It has been pretty much 16 weeks from the start but these last two months I’ve been going over my “maintenance” a lot and still keep losing weight at a pretty hefty pace.
    2. I should have lost 2.8kg or less - since I’ve been going over often - but I’ve lost 6.3lg
    3. About 150 extra calories? I’m estimating how many I’ve burned so it’s not exact (I estimate each 1hr gym session to be 300 cals burned 3-4x a week)

    My hormones are all out of whack so I’m not sure how accurate that is for my body but hopefully the doctor will be able to get them fixed so I’ll keep that in mind for the future!

    If you're losing faster than expected and you feel confident that your food measurement is accurately, then a likely answer is that 1) you can eat back your exercise calories and 2) your activity level is probably higher than what you estimated when you set your goals.

    Keep in mind that your activity goal is just an estimate. Some people over-estimate how much activity they're doing, but many people also under-estimate their activity level. College students aren't exactly like desk workers. Although you're sitting for part of the day, you're also moving between classes, walking to various things, etc. College students can absolutely be sedentary, but it's also possible for the everyday activity you're doing to move you into a more active category.

    This is a process where we are responsible for monitoring our real-life results against our estimates and making the necessary adjustments. No computer program is going to be able to predict with absolutely accuracy how much energy you're using.

    Thank you for your reply!

    I’m a high school student so I move between classes and up and down stairs every hour or so. I’ve put in my activity level as “lightly active”.

    My gym sessions are usually 1hr 15 minutes. I weigh 52kg-ish right now and do 30 of walking at 3mph at 15% incline and 45 minutes of moderate-level weight training. I estimate I burned about 300 calories and so I try to eat 150 of those back.

    Would you mind telling me if you think these estimates are reasonable? I would really appreciate it
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    Wow! May I ask how you manage to estimate your calories burned so well?
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    FitToFatToFitAgain wrote: »
    Wow! May I ask how you manage to estimate your calories burned so well?

    Personally: I have a Fitbit synced to my MFP account. It handles all the adjustments for me. I know from paying attention to results over time that the estimates are accurate.

    But I know people here who have had success doing it a variety of different ways. The important thing is to pick a method, use it for a reasonable period of time, and then make adjustments based on your real life results (whether you're losing faster or slower than expected).
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    FitToFatToFitAgain wrote: »
    janejellyroll wrote: »
    FitToFatToFitAgain wrote: »
    One thing is you underestimating the calories you’ve consumed and another is MFP’s suggestion of how many calories you should consume. I went to see a dietician and she said that even at my being a 5ft nothing woman I should be eating more than 1200 calories since I’m not completely immobile all day everyday even though MFP tells me it would have me at a healthy rate of weight loss 🤷‍♀️

    What is your current weight? 1 pound a week may not be a realistic goal for you. MFP gives you a goal that is based on your desired rate of loss. For those of us who don't have a lot to lose, 1,200 will often show up with a goal that is too aggressive because MFP can't go any lower than that. On top of that, MFP is expecting for you to eat *all* your exercise calories, so if you're intentionally not doing that it isn't surprising that you may not be eating enough.

    I’ve been eating half since I’ve read that most people tend to over estimate calories burned, so eating half of them back will reduce the chances of eating more than you burned but that could totally be the case!

    Right now I’m 51.7 so pretty much 52kgs (115 pounds I think) and I’m 5ft tall. I started off at 65kg eating 1200 a day and eating back all of my “exercise calories” AKA me walking at around mid November so 4 months back. I don’t really have a goal weight, just kind of looking at my body and seeing where it’s at. I have a fairly muscular build naturally so I usually weigh more than others even if at a lower body fat which is why I don’t use BMI.

    First things first, you're already a normal weight so 1 pound a week isn't a reasonable goal for you. I would change it to .05. Since you're already close to goal, weight loss is going to be a slow and steady thing for you.

    Second, to your question about your calorie burn estimate: I'm honestly not sure since I don't do a lot of weight training (I'm more like 15-20 minutes a day of body weight resistance training and then more running).
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    Yeah I am at a normal weight, so I’m just trying to reduce my body fat percentage at this point. Before, I was pretty much obese but now I’m at a normal weight AND my body is healthier!

    Thanks anyways, I appreciate you helping me with all of this!

    Also, I’m a teen trying to save up for uni and mes school so I’m much too broke for a Fitbit, but thanks anyways! In case I can ever get one, can I ask which model you have that you find accurately estimates your calories burned?
  • janejellyroll
    janejellyroll Posts: 25,763 Member
    FitToFatToFitAgain wrote: »
    Yeah I am at a normal weight, so I’m just trying to reduce my body fat percentage at this point. Before, I was pretty much obese but now I’m at a normal weight AND my body is healthier!

    Thanks anyways, I appreciate you helping me with all of this!

    Also, I’m a teen trying to save up for uni and mes school so I’m much too broke for a Fitbit, but thanks anyways! In case I can ever get one, can I ask which model you have that you find accurately estimates your calories burned?

    I use a Charge 2 (the newer model is the Charge 3, which I've heard also works well).

    But you don't need a Fitbit in order to do this! You already have the real life results you need to make your adjustments. Since you know that you are burning more than you estimate, you can start by eating back all your exercise adjustments, observe what happens over a few weeks, and then make any additional adjustments that you need. Good luck! It sounds like you've already had amazing results and now you're just working on the "finishing touches" which is a slower (but still rewarding) part of the process.
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    Thank you for all of your help! I really appreciate it!
  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    AnnPT77 wrote: »
    Because I didn't see anyone else say this (in fact, saw something close to the contrary):

    It is entirely possible for MFP to underestimate your calorie needs, even wiith accurate settings.

    It's even possible for it to underestimate by quite a lot. This is very unusual. No one should believe it is happening for them, until they have multiple months of careful logging/tracking data**, and for younger women, at least a couple of full menstrual cycle so weights at the same point in the cycle can be compared.

    I'm somewhere on the border of sedentary and lightly active, according to the step-based definitions. If I set MFP at active (full active) it still underestimates my daily calorie needs by a couple of hundred, based on almost 5 years of careful logging practice.

    Once you have a couple of months (full menstrual cycle at least) of careful logging data, use your own logging data to adjust your intake to achieve the weight loss rate that's sensible for you (which, in your case, I agree would be 0.5 pounds/week at most).

    At that point, when you have enough of your own solid data, it doesn't matter what the "calculators" say. It doesn't matter whether you know a reason why they're wrong for you (if they are), as long as you're healthy. (Ask your doctor for tests, if you're worried. I did.)

    The calculators are not a magic oracle of singular truth. They're just a statistical estimator that takes a few data points, and spits out the mean value for people of your characteristics, based on large-scale research. Underneath, it's a bell curve. Most people are close to the mean (small standard deviation). But someone's out closer to the high and low tails of the curve . . . it's just that it's a tiny number of people. It's unlikely and improbable that you're one of those people, based on pure statistical definitions of "improbable", but it's not impossible.

    ** If, after the first month, someone seems to be losing riskily fast, they should eat somewhat more, and keep tracking. It will be possible, through careful data analysis, to sort out the results of a controlled calorie increase. Sorting out the physical consequences of persistent undernutrition is potentially much harder.

    Thank you for all of your advice, I really appreciate it. As some health problems have gotten in the way, I haven’t been able to be consistent with the number of times I go to the gym in a week. With my gym closing it’s doors and extracurriculars + school being suspended for now, maybe I’ll be able to gain some consistency and adjust accordingly ☺️ Since I wasn’t tracking this entire week but I most definitely went over my maintenance and have still lost weight, at this point it’s hard for me to tell how many calories I should be eating, but some consistency in my routine will help clear that up soon enough so thanks for all of your help

  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    PAV8888 wrote: »
    I don't understand!

    What the flying **kittens** does it matter what your estimates tell you that you should be doing when your real life feedback is that you're losing faster than expected??????????

    Eat more!

    Plus within normal weight you have no reason to be trying to lose so fast.

    You may want to use a weight trend application to smooth out your day-to-day variations and just look at your longer-term weight changes.

    You may also want to carefully look through your data to get an idea about your expected monthly hormonal weight variations to differentiate them from longer term weight level changes.

    Lastly with some inaccuracies in your logging you may want to adopt a little bit more a little bit less method. In that you may not need or want to intervene unless your weight trend exceeds a certain pre determined level, or a certain rate of change.

    to me it sounds like you're almost paralyzed to make the decisions you need to make to stabilize for fear that you may overshoot.

    But even if you do over shoot and start going in an unwanted direction you're not powerless to detect that and intervene when it happens.

    Most of us have not gotten up in weight consistently and over time without feeling quite full quite often while simultaneously being unwilling or unable to do anything about it.

    Yes, I get that I’m not in a powerless position here and the hormone thing would be helpful and my hormones weren’t all screwed up.

    That being said, I’m glad you have such a healthy relationship with food and your body that you’re able to just “eat more”, but to me - and probably many others - it’s not that simple. I have a tendency to eat beyond when I’m full - sometimes even to the point where I’m so full I get sick. Experimenting with the number of calories within my deficit is scary to me because I’m not as in tune with my body as of right now to go for a more “intuitive eating” approach and adjust from there.

    Yes, I’m in a healthy weight range right now, but as I’ve mentioned previously I wasn’t that long ago. As a former competitive athlete who trained basically during all of my free time, I still feel like I need to lose some more body fat to fit my own standards. Granted, the “need” isn’t actually there, but since this approach has lead me to tone up significantly, my weight still dropping considerably despite building more muscle - which weighs more than fat - is something I look at.

    So thank you for all of your advice. Hopefully, some day I’ll be in tune enough with my body to take it in full, non-restrictive strides. But for now, I’m just not at the point where I can just “eat more” and not risk overdoing it on a regular basis. This is not just about gaining back weight, but my relationship with food as a whole and how I need to focus on listening to my hunger cues over how good the food looks 😂

    Again, thanks and I hope you understand what I’m trying to say 😊
  • NovusDies
    NovusDies Posts: 8,940 Member
    FitToFatToFitAgain wrote: »
    AnnPT77 wrote: »
    Because I didn't see anyone else say this (in fact, saw something close to the contrary):

    It is entirely possible for MFP to underestimate your calorie needs, even wiith accurate settings.

    It's even possible for it to underestimate by quite a lot. This is very unusual. No one should believe it is happening for them, until they have multiple months of careful logging/tracking data**, and for younger women, at least a couple of full menstrual cycle so weights at the same point in the cycle can be compared.

    I'm somewhere on the border of sedentary and lightly active, according to the step-based definitions. If I set MFP at active (full active) it still underestimates my daily calorie needs by a couple of hundred, based on almost 5 years of careful logging practice.

    Once you have a couple of months (full menstrual cycle at least) of careful logging data, use your own logging data to adjust your intake to achieve the weight loss rate that's sensible for you (which, in your case, I agree would be 0.5 pounds/week at most).

    At that point, when you have enough of your own solid data, it doesn't matter what the "calculators" say. It doesn't matter whether you know a reason why they're wrong for you (if they are), as long as you're healthy. (Ask your doctor for tests, if you're worried. I did.)

    The calculators are not a magic oracle of singular truth. They're just a statistical estimator that takes a few data points, and spits out the mean value for people of your characteristics, based on large-scale research. Underneath, it's a bell curve. Most people are close to the mean (small standard deviation). But someone's out closer to the high and low tails of the curve . . . it's just that it's a tiny number of people. It's unlikely and improbable that you're one of those people, based on pure statistical definitions of "improbable", but it's not impossible.

    ** If, after the first month, someone seems to be losing riskily fast, they should eat somewhat more, and keep tracking. It will be possible, through careful data analysis, to sort out the results of a controlled calorie increase. Sorting out the physical consequences of persistent undernutrition is potentially much harder.

    Thank you for all of your advice, I really appreciate it. As some health problems have gotten in the way, I haven’t been able to be consistent with the number of times I go to the gym in a week. With my gym closing it’s doors and extracurriculars + school being suspended for now, maybe I’ll be able to gain some consistency and adjust accordingly ☺️ Since I wasn’t tracking this entire week but I most definitely went over my maintenance and have still lost weight, at this point it’s hard for me to tell how many calories I should be eating, but some consistency in my routine will help clear that up soon enough so thanks for all of your help

    You cannot always connect scale results with recent eating or habits. It could easily be weight loss that has shown up because you released some water retention. That is why you must evaluate your results over a longer stretch of time.

    If you weigh daily look for a low weight from 6 or more weeks ago. Look for your most recent low weight. Subtract those and divide by number of days in between. Multiply that times 3500 and you will have your average daily deficit. 250 would be a half pound a week. I tend to give myself a ~100 calorie margin so if it were me I would add anything over about 350 back into my daily eating.

    If you need any help with the math you can give me the weights and their corresponding dates and I will do it for you.

  • FitToFatToFitAgain
    FitToFatToFitAgain Posts: 14 Member
    NovusDies wrote: »
    FitToFatToFitAgain wrote: »
    AnnPT77 wrote: »
    Because I didn't see anyone else say this (in fact, saw something close to the contrary):

    It is entirely possible for MFP to underestimate your calorie needs, even wiith accurate settings.

    It's even possible for it to underestimate by quite a lot. This is very unusual. No one should believe it is happening for them, until they have multiple months of careful logging/tracking data**, and for younger women, at least a couple of full menstrual cycle so weights at the same point in the cycle can be compared.

    I'm somewhere on the border of sedentary and lightly active, according to the step-based definitions. If I set MFP at active (full active) it still underestimates my daily calorie needs by a couple of hundred, based on almost 5 years of careful logging practice.

    Once you have a couple of months (full menstrual cycle at least) of careful logging data, use your own logging data to adjust your intake to achieve the weight loss rate that's sensible for you (which, in your case, I agree would be 0.5 pounds/week at most).

    At that point, when you have enough of your own solid data, it doesn't matter what the "calculators" say. It doesn't matter whether you know a reason why they're wrong for you (if they are), as long as you're healthy. (Ask your doctor for tests, if you're worried. I did.)

    The calculators are not a magic oracle of singular truth. They're just a statistical estimator that takes a few data points, and spits out the mean value for people of your characteristics, based on large-scale research. Underneath, it's a bell curve. Most people are close to the mean (small standard deviation). But someone's out closer to the high and low tails of the curve . . . it's just that it's a tiny number of people. It's unlikely and improbable that you're one of those people, based on pure statistical definitions of "improbable", but it's not impossible.

    ** If, after the first month, someone seems to be losing riskily fast, they should eat somewhat more, and keep tracking. It will be possible, through careful data analysis, to sort out the results of a controlled calorie increase. Sorting out the physical consequences of persistent undernutrition is potentially much harder.

    Thank you for all of your advice, I really appreciate it. As some health problems have gotten in the way, I haven’t been able to be consistent with the number of times I go to the gym in a week. With my gym closing it’s doors and extracurriculars + school being suspended for now, maybe I’ll be able to gain some consistency and adjust accordingly ☺️ Since I wasn’t tracking this entire week but I most definitely went over my maintenance and have still lost weight, at this point it’s hard for me to tell how many calories I should be eating, but some consistency in my routine will help clear that up soon enough so thanks for all of your help

    You cannot always connect scale results with recent eating or habits. It could easily be weight loss that has shown up because you released some water retention. That is why you must evaluate your results over a longer stretch of time.

    If you weigh daily look for a low weight from 6 or more weeks ago. Look for your most recent low weight. Subtract those and divide by number of days in between. Multiply that times 3500 and you will have your average daily deficit. 250 would be a half pound a week. I tend to give myself a ~100 calorie margin so if it were me I would add anything over about 350 back into my daily eating.

    If you need any help with the math you can give me the weights and their corresponding dates and I will do it for you.

    I usually don’t even weigh myself once a week, this was just something that surged.

    If all of my tracking and calories and such are to a T which sometimes they are but over the last two months I’ve been overeating and not really tracking certain things properly, by your calculations I’m in a 400 calorie deficit every single day. Assuming that I never went over my calories or exercised, that would be a net of 1300 calories a day. Since I never eat over a net of 1300 when I track, even when having exercised, I assume that I must be either very accurate with my calories burned estimate when exercising or burning much more than expected for my constant overeating to result in this deficit.

    Thank you! This is very illuminating and helpful in seeing where the problem may lie!

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