Weight Loss
Moderators: spoiled_candy, Mollybygolly, coach_k, devilish_patsy, nycgirl


My scale gives different readings - which one do I choose?


Quote  |  Reply

I can weigh myself, and then someone else can step on it right after me (whether it's my 40 lb daughter or my 215 lb hubby) and if I step on it again it will be off by about 1/2 to 1 lb. I got 3 different readings this morning (184.5, then 185.5, then 185) so which one should I log? The lowest, the average of all 3, or the highest? It said 184.5 yesterday (I only weighed once) and that was the first reading it gave me today. The scale is only a few months old and just started doing this so I know it's not broken. My last one did the same thing after a while, which is why I got the new one. But I've heard other people say their scales do the same thing sometimes. Help?

*edited for spelling

16 Replies (last)

Take the first reading and only step on once.  And try not to weigh daily because your body-weight fluctuates for all kinds of reasons from day to day.  Bathroom scales aren't especially precise at the best of times so all you're looking for is the trend.  If you're the same or lighter this time next week, that's success...

Original Post by gi-jane:

Take the first reading and only step on once.  And try not to weigh daily because your body-weight fluctuates for all kinds of reasons from day to day.  Bathroom scales aren't especially precise at the best of times so all you're looking for is the trend.  If you're the same or lighter this time next week, that's success...

 And thats the truth.

Though I do weigh daily to get an idea of how different foods & times of the month affect my weight. Purely for myself- it doesn't affect the way I feel for the rest of the day (though I do smile if its a little lower! LOL!).

To answer your question simply - scales just aren't that accurate. Weigh yourself once, and accept whatever number it gives you. If you can clear the scale before you get on (sometimes just tapping it to go to zero), you can try that, and see if it gives better results.

But I do think it's fine to weigh every day, as long as you can handle seeing the daily variation (i.e. be as calm about a three pound gain as a three pound loss). Yes, your weight will fluctuate (and the inaccuracy of scales doesn't help). I found weighing every day gave me a better perspective on those fluctuations.  I think about it this way. If I weight every day, I might get these results:  

M 135.6 - T 135.4 - W 135.4 - Th 135.2 - F 135.6 - Sa 135.0 - Su 134.8 - M 135.8.

If I only weighed on Mondays, I might think I'd gained 0.2 pounds. If I weigh every day, I see that I've pretty much been going down, even as far as 134.8, but Sunday night nachos made me jump up to 135.8 just for Monday. Tuesday, I could be back to 134.8, but I wouldn't see it, because I only weigh on Monday.

To each his own - just find what makes you less crazy. If you find that you get very upset at a fluctuation, daily weighing isn't for you.

Thanks for the responses.

I do weigh every day but I have learned not to get upset at fluctuations, unless it goes up and stays up for more than 3 days. Then I get a little crabby, lol.

My main concern was the scale giving me 3 different readings this morning. I actually do usually do what gi-jane says and only weigh once, but my hubby is the one that pointed out the flaw so I tested it out this morning. It was aggravating, but from now on I'm just going to only step on it once. I should've been excited because I lost 3.5 lbs this week, but instead I was upset because of the scale. I'm going to put this whole scale fiasco behind me and celebrate a 3.5 lb loss, because that's a huge amount of weight. (And well deserved! I was working hard and not seeing results for a while, so I needed to see that loss!)

Thanks again.

I would go with the first one, and keep everyone off the scale. You should be the first one to use it. I told my kids, and fiance.. This is mines, and not yours.. Get your own.. Step on it once, and take the first reading and run with it.. Now.. If you are like 10 pounds off.. Like I was once.. Then you question the reading.. I mean.... Really look into it. You can't get a good reading on carpet.. The floor has to be leveled. But really.. Keep everyone off the scale you use.. Just to be on the safe side.

Edit
To change a word.

I only weigh myself on days that i go to the gym, it just makes me try to work that much harder to see what i weigh midday. i usually step on the scale three times just like yourself and i go with the higher weight, i figure that if that is wrong and i actually weigh less it'll make me feel better than going with the lower weight and finding out that i'm actually a few pounds heavier. it's a mind game for me. and i really hate this game!
Original Post by gi-jane:

Bathroom scales aren't especially precise at the best of times so all you're looking for is the trend. 

 Bathroom scales aren't especially acurate, but they are all pretty precise.

I weigh myself often. But a few times out of the week. Everyday when I've gained some weight I had no business gaining. I use to step on the scale as often as you did in the morning, but running with the first weight with me is the best option. I don't have time for the mind game, and I use to play them often.

I weigh less when my weave is up.
maybe I should take everything off this time around.
I have to make sure I wake up.. Let my body adjust, and then weight at 6.

Going through all of these changes can drive  me nuts. SO I had to pick one number, and one set time to weigh.

I wish you luck on your weight loss.

Original Post by floggingsully:

Original Post by gi-jane:

Bathroom scales aren't especially precise at the best of times so all you're looking for is the trend. 

 Bathroom scales aren't especially acurate, but they are all pretty precise.

sorry sully -- gi jane was right.  Precision means how "reproducable" a number is, so our OP's scale isn't very precise, or she would get the same number every time.  It is probably fairly accurate, or close to the true number, plus or minus some degree of deviation.  I think it is more true to say scales are fairly accurate, even if they are not very precise. 

 

I agree, bathroom scales aren't precise because of springs and stuff like that.

I just step onto  my scale like 3 times and take the lowest number lol, tricking the scale and tricking myself! :D

I find my first reading is the most far off.  Weighing today, I found variation of approximately 4 pounds, including that first reading I never believe.

I live in an old house converted into apartments.  There is a definite floor slant and I feel that causes much of my variation.  Today was worse than most, but I probably stepped on it 10 times until I found the spot where i could get the same reading three times in a row.  That is what I logged.

The problem of the multiple weights shown on repeated measuring is not a problem of either preciseness or of accuracy. 

PRECISION refers to how close the multiple readings are to each other.   A scale that reads 180, 180.3, and 179.8 is very precise compared to one that shows 180, 187 and 184.  May be completely inaccurate, but it's very precise. 

ACCURACY has to do with how close to your true weight the scale readings are.  If you actually weigh 184 and the scale reads 185.5, the accuracy of the scale is off by 1.5 lbs.   

The problem is the lack of RELIABILITY.  Reliability means having a consistency of measurement across multiple measures.   Essentially, a perfectly reliable scale would give you the exactly same reading when the same weight is placed on it over and over again. 

The variability in the different readings is called "measurement error."  You don't know how much that measurement error really is unless you have another scale to compare with - one that you KNOW measures your TRUE weight. 

Essentially, with a scale that is less reliable, you have less certainty that your true weight is within a particular range.   Less certainty increases the "margin of error."   Your margin of error now is 185 plus or minus .5 lb. 

You can be reasonably confident that your true weight is very probably within .5 lb of 185.  You should consider .5 lb to be a reasonable confidence interval for any time that you weigh yourself.  

End of statistics lesson   ;-)

No scale is ever perfectly reliable.  Regardless of whether you log the first, the highest, the lowest, or the average weight, using a consistent method is probably more important for our purposes, which is to monitor CHANGES.

#13  
Quote  |  Reply

omg, let's capitalize more laboratory terms in this thread.


I weigh myself everyday on a $50,000 analytical scale. I then weigh a control version of myself, which is a life-size dummy made out of ballistics gelatin, based on the dimensions of my body before I started dieting.

I plot both weights, and publish them in a peer-reviewed weightloss journal, where my results are subjected to the scrutiny of the PhDs all over the world. Later that day, a weight-loss conference is held in either Vienna or Copenhagen, where a panel discusses whether the change in my weight is due to dieting, exercise, or carpet pile depth. Later that night, the panel releases its findings, and I go to bed.


If you don't weigh yourself like I do you will not know if you're making progress. Trust me.

*sigh*

Throws $25,000 analytical scale in trash and pulls out scientific catalogue.

 

Who knew?

LOL!!

Thanks everyone for the suggestions. I'm just going to take the first weight it gives me. And stop freaking out about how accurate it is. Like rjs243 said, the margin of error is probably only about .5 lbs either way, so that's nothing to worry about.

Thanks again all!

16 Replies
Recent Blog Post
When life throws you a curve, you are left with one very important choice: how you react. When you don’t get that promotion, do you react by overeating? Instead, make the choice to

Continue reading...