Can the scale give you a false low reading?

LMHinson15
LMHinson15 Posts: 201 Member
edited November 10 in Health and Weight Loss
I know when our bodies retain water that we can get a "false high" reading on the scale(a reading that is higher than our actual body fat/lean muscle weight)

Is there any situation that would create a false low reading?

I always weigh multiple times to get a steady number, but this week's number surprised me (in a good way, if it's real!). I can't logically think of a way that the scale would read consistently less than what is standing on top of it... so I'm sorry if this sounds like a totally ignorant question.

Thoughts?

(sorry if there is a conversation about this elsewhere, I did search first and didn't see anything)
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Replies

  • jacksonpt
    jacksonpt Posts: 10,413 Member
    Sure. Assuming you're weighing yourself the same day of the week and a the same time of day, 3 reasons immediately come to mind:
    - the scale isn't calibrated correctly
    - the scale isn't on a flat, even, firm surface
    - you're feet are positioned differently on the scale (even an inch here or there can matter).

    If you're weighing yourself multiple times and taking the average, then I doubt the last one applies. I would hope you're smart enough to be using a decent scale on a hard, flat, level surface, so I'm going to assume the second one doesn't apply. So really it's just a question of whether or not the scale is dialed in correctly.
  • Nicola0000
    Nicola0000 Posts: 531 Member
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.
  • jacksonpt
    jacksonpt Posts: 10,413 Member
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.
  • iaemmy
    iaemmy Posts: 13 Member
    If it is digital, it can give false readings if your battery is wearing out.
  • shelby623
    shelby623 Posts: 55 Member
    Yes! My scale told me I gained 7 lbs in 2 days...

    To check the calibration of a digital scale, I put one of my 20 lb weights on it to see what the scale is actually reading.
  • TheUnwritten
    TheUnwritten Posts: 158 Member
    IMO the real scale is the mirror. The scale can drive one crazy. I learned that when i first began dieting and exercising.
  • Roshams
    Roshams Posts: 77
    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.
    [/quote]



    I actually stopped weighing myself after my workout because I weigh more.

    I just try to keep it to once a week, same time in morning BEFORE breakfast, and totally naked. Then my weight will be as low as possible! lmao. Call me crazy, but it make me feel better ;)
  • SergeantSunshine_reused
    SergeantSunshine_reused Posts: 5,382 Member
    Yes it can get a false low.

    If you had lower carbs the day before and got on the scale you might notice more water weight lost
    or if you do a ton of cardio the night before\
    sodium was lower then normal

    stuff like that
  • AmyjoyHa
    AmyjoyHa Posts: 9 Member
    While all these things are true, there is one more explanation..... You could have totally rocked it this week!
  • kdelost630
    kdelost630 Posts: 196 Member
    It could be a "false" reading if you are really dehydrated. I weighed myself once after a night of drinking and had an excellent number on the scale, but it took a while to actually get there when I was hydrated...But that being said, log it. It may not be false.
  • Mmissy104
    Mmissy104 Posts: 39
    unless its drastically low it could just be weight loss. I have friends who will lose 1/2 a pound one week nothing the next week than the third week drop like 6 lbs. That doesnt happen all the time but its not uncommon.

    Also calibration could be an issue but if its the same scale you have been using than i doubt it.

    Did you weight at the same time of day? I can sometimes weigh 5lbs differnt just from day to night.

    Make sure its on a hard flat surface, no carpet, or slopes.

    And i agree with jacksonpt I usually weigh more after a workout. Ya i sweat ALOT, but i also drink ALOT of water during a workout too, im betting I drink alot more than im sweating out.
  • Roshams
    Roshams Posts: 77
    While all these things are true, there is one more explanation..... You could have totally rocked it this week!

    Probably true ;)
  • Brunner26_2
    Brunner26_2 Posts: 1,152

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    I think it would depend on the workout and the conditions. I've weighed myself before and after marathon training runs in the summer. I lost a couple pounds, which I attributed to sweat. Obviously it's only temporary.
  • sarafil
    sarafil Posts: 506 Member
    I usually weigh more after a work out.
  • UpEarly
    UpEarly Posts: 2,555 Member
    Sure! You can absolutely get a false low reading.

    Over the holidays, I had a stomach virus. I lost ten pounds in three days. Was it actual body weight from fat/muscle mass? Nope - some of it may have been actual body mass (I hardly ate for five days) but most of it was water. I was really, really dehydrated from being so ill. As soon as I started eating/drinking again, most of the weight came right back.

    Also - in the summer - if I do a long workout on a hot day, I can sweat off seven pounds in 90 minutes. It's all water, and I 'regain' all the weight as soon as I rehydrate.
  • Elizabeth_C34
    Elizabeth_C34 Posts: 6,376 Member
    Honestly, it doesn't matter.

    Just be consistent about when you weigh and how you weigh to track your progress.

    Weigh at the same time every day (if you weigh daily). Be consistent with your carb and sodium intake, and make sure you position yourself on the scale in the same way (I marked my scale with pieces of tape to show where my feet should go).

    The actual number really doesn't matter.

    To answer you directly, I always take the lowest reading, and I weigh early in the morning. Is it anomalously low? Maybe. But it's consistently so. The upward fluctuations I don't care about though they can be annoying if they persist. After doing this for over a year, I can see my trend very clearly.
  • CountryBoy65
    CountryBoy65 Posts: 908 Member
    No, it cannot happen. Scales are never wrong.
  • UpEarly
    UpEarly Posts: 2,555 Member
    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    Sheesh - I must sweat like a crazy hose beast! LOL In the summer, if I go for a 60-90 minute walk/jog/hike on a hot summer day, I always lose anywhere from 4-8 pounds. It can't be fat loss, so it has to be the water I sweated out.

    In my experience, weight loss from sweating can be VERY significant.
  • hexrei
    hexrei Posts: 163
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    For a person my size ~180 lbs, my weight frequently fluctuates by up to five pounds in a day based on water and bowel content. A half hour of running alone can cost me 1-2 pounds, and if I was out drinking the night before and wake up dehydrated as a result it can mean an even more drastic loss.
  • jodywalsh
    jodywalsh Posts: 7 Member
    I am so glad you said that...i too weight once a week (tue) in the AM before I get in the showe and totally naked. I just figure its the REAL ME!!! lol!
  • Coyla
    Coyla Posts: 444 Member
    Dehydration may cause a lower than normal reading. But you will notice other symptoms of that, like a severe headache, dry skin, etc. If you feel healthy and normal, then you're probably just having a great weigh in.

    It's possible your weight may go up a little next week or stagnate a bit, but that's normal.
  • MinnesotaManimal
    MinnesotaManimal Posts: 642 Member
    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    Sheesh - I must sweat like a crazy hose beast! LOL In the summer, if I go for a 60-90 minute walk/jog/hike on a hot summer day, I always lose anywhere from 4-8 pounds. It can't be fat loss, so it has to be the water I sweated out.

    In my experience, weight loss from sweating can be VERY significant.


    you are not alone. I am well into a healthy weight range and I still fluctuate 3-8 lbs from an hour+ of working out, even at room temp( gym) or in freezing or sub freezing weather when running outside.

    but I also flux up to 10 lbs ( average is 4-5 lbs) between bed time and morning after taking a leak.... figure that one out.
  • minadeathclutch
    minadeathclutch Posts: 375 Member
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    I also weigh a LOT more after a workout.. 3-4 lbs more!
  • matthewparmenter
    matthewparmenter Posts: 28
    If it is digital, it can give false readings if your battery is wearing out.

    Quoted for truth, I've had this happen on my digital scale several times! New batteries always brings it back to normal.
  • matthewparmenter
    matthewparmenter Posts: 28
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    I sweat pretty heavily, so it's not uncommon for me to lose up to 2-3 lbs after a strenuous workout even if I drink water while I'm at it.
  • LMHinson15
    LMHinson15 Posts: 201 Member
    While all these things are true, there is one more explanation..... You could have totally rocked it this week!

    Probably true ;)

    I certainly would like to THINK this is the case.

    Thanks for all the input!

    I'm well hydrated, and weigh the same time of day every time usually after a normal workout.
    The scale is level, and the batteries are relatively fresh. I'll have to remember to check the calibration.

    I'll take it as a good loss for this week! I was just interested to know.

    Thanks everyone!
  • hexrei
    hexrei Posts: 163
    it can do as you can lose water. If you weigh yourself before and after a heavy workout, then the scale can change from loss of water through sweat. But this would only be water, not fat, so it would go back up again when hydrated.

    While this is true that you do lose water through sweat, IME it's rarely significant, especially considering you retain water due to the muscle stimulation. I frequently weight more after a workout than I do before.

    Curious to see what others have to say about this.

    I also weigh a LOT more after a workout.. 3-4 lbs more!

    This is going to be a result of eating and drinking following your workout. Weigh yourself *right* after (and assuming you sweat while you work out as most do) you will weight less, albeit if you don't sweat much it won't be much less.
  • doublezizzle
    doublezizzle Posts: 42 Member
    To check the calibration of a digital scale, I put one of my 20 lb weights on it to see what the scale is actually reading.
    [/quote]

    great idea! why didn't i think of that?? so simple :)
  • WickedGarden
    WickedGarden Posts: 944 Member
    I guess...I have done the 20# weights to check the scale, and it calibrates correctly.

    I can weigh myself before I go in for a doctor's visit, and it gives me one number, then when I get weighed at the office (less than an hour later), it gives me a number 10 pounds higher! OH it's maddening! Mainly because my doctor gives me the "you really need to lose weight talk"
  • john233
    john233 Posts: 27
    very good post. I look forward to reading more. Cheers.
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