Body fat % scale accuracy?

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drewlfitness
drewlfitness Posts: 114 Member
edited June 2015 in Health and Weight Loss
I own a scale that shows me how much I weigh, and also shows my body fat %.

Over the last 2+ months, I have been eating a caloric deficit, but I have also been lifting heavy, thereby building muscle.

I have in fact lost weight, although some weeks I see no change, and some weeks I do (likely due to muscle building and/or too much sodium in diet).

In the last 25 lbs of weight loss, I have absolutely slimmed down, tightened up, visually less fat on my body, although, the body fat % that the scale returns is almost identical every time I weigh myself, whether I had been "bulking" that week or "cutting" by eating slightly less than my already reduced caloric goal, and more cardio.

My question is, has anyone experimented with the Taylor scales and seen them to be accurate, while doing a caloric deficit combined with muscle building regiment? My conclusion is that there is no way my body fat % has remained the same during the last 25 lbs of weight loss, because if anything, I have put more muscle on, and have lost an overall 25 lbs, it's quite obvious when looking in the mirror...
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Replies

  • crazyjerseygirl
    crazyjerseygirl Posts: 1,252 Member
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    I can't speak to Taylor scales but I will give you this anecdote.

    I have a WiThings scale, it claims to estimate body fat. It estimated my body fat at 15.5% when I was about 100lbs overweight. I'm also female so 15.5% is VERY low.

    Basically it was full of crap. Ymmv
  • juggernaut1974
    juggernaut1974 Posts: 6,212 Member
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    They are not terribly accurate.

    Hydration level alone can throw the reading off a few percentage points.
  • Sued0nim
    Sued0nim Posts: 17,456 Member
    edited June 2015
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    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress
  • senecarr
    senecarr Posts: 5,377 Member
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    They're pretty inaccurate. If used under the same conditions (early morning after reducing water weight) they can kind of track changes.
  • Sued0nim
    Sued0nim Posts: 17,456 Member
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    Mine is roughly 6-7% points out
  • bpetrosky
    bpetrosky Posts: 3,911 Member
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    All consumer scale bioimpedance readings are inaccurate. The best you can hope for is that they're at least consistently inaccurate, so that you can look for a trend over time.

    You can get a cheap body tape measure or caliper and use some simple calculations to give a different estimate. These are also inaccurate, but I use the body tape once a week and three of the common formulas (Navy, YMCA, Modified YMCA). Excel makes that very easy. Again, inaccurate, but they tend to trend well.

    My Eat Smart scale also has a BF% function, it trends about 5% lower than the body tape calculations.

    There are bioimpedance scales made for clinical settings that are more accurate, but they still can't match hydrostatic or DEXA scans for accuracy.
  • heybales
    heybales Posts: 18,842 Member
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    Consumer Reports used to test them years back - the methods by which they work haven't change since.
    But they stopped because accuracy was just too bad in general.

    The could be upwards of 5% accurate, if a properly hydrated body was presented. But normally around 10%. Obviously could be worse too.

    But you'd never know if yours was, without a comparison.

    They did find some that were at least consistent. So accuracy may have been off, but at least they would show you a trend one way or another because it was always inaccurate by same amount. Others could bounce around in that 5-10% accuracy so you could go months without knowing something was actually happening.

    You do need valid weigh-in, just like normal, to minimize known expected water weight fluctuations.
    Morning after rest day eating normal sodium levels, not sore from last workout.

    Anything else is just noise.

    Also, since most are only feet based, path of measurement is up one leg and right down the other.
    Electricity and path of least resistance, right. Rest of your body is unknown. Tables are built for the stats it has, what it does see, and assumptions are made.
    Hence the reason you'll find scales that have athlete mode.
    Or have feet and hand sensors to get a 3 way cross look.
  • rsclause
    rsclause Posts: 3,103 Member
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    I have the aria scale from fitbit and have no idea how accurate it is. I can say that my body fat % did go down but very little until I really upped my cardio to about 30 miles a week, lifted three days a week and worked abs daily. All this was with a deficit and eating back most of my exercise calories. I think I was at about 15% when I reached my ideal weight. I have since put about 20 pounds back on and then lost about 5 lbs. of that already but my belly returned and body fat went to and still is 23%. I suspect it will start to slowly drop again as I get rid of my remaining fat.
  • davert123
    davert123 Posts: 1,568 Member
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    I agree with the above. My experience is that body fat measuring scales do not work with sufficient accuracy to be useful (sorry). I've adopted a tape measure and the army body fat calculation method. Seems nearly as good as anything. Callipers seem like a good idea but my experience is that it is difficult to get repeatable results with them whereas measuring is simple and repetitive.
  • drewlfitness
    drewlfitness Posts: 114 Member
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    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    I'm not new to weight lifting. I've lost 25 lbs, but my shirts are basically tighter in shoulders, pictorial area, and my back and traps have larger muscles. If I've lost 25 lbs, but my shirts are either the same or tighter, then what would you conclude?

    Also, I add calories back from exercise. I burn around 800 calories a day at the gym from lifting and cardio, and I add roughly 75% back. This means that I typically consume 2800 calories a day, eventhough my starting goal was 2200. I'm 6'1", 242lbs. I am fairly certain that my body builds muscle quicker/easier than average males.
  • senecarr
    senecarr Posts: 5,377 Member
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    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    I'm not new to weight lifting. I've lost 25 lbs, but my shirts are basically tighter in shoulders, pictorial area, and my back and traps have larger muscles. If I've lost 25 lbs, but my shirts are either the same or tighter, then what would you conclude?

    Also, I add calories back from exercise. I burn around 800 calories a day at the gym from lifting and cardio, and I add roughly 75% back. This means that I typically consume 2800 calories a day, eventhough my starting goal was 2200. I'm 6'1", 242lbs. I am fairly certain that my body builds muscle quicker/easier than average males.

    242 lb now, so you were 267 lb? I wouldn't put it out of the realm of possibilities you gained some muscle mass.
    I'm assuming your main lifts went up in volume?
  • drewlfitness
    drewlfitness Posts: 114 Member
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    bpetrosky wrote: »
    All consumer scale bioimpedance readings are inaccurate. The best you can hope for is that they're at least consistently inaccurate, so that you can look for a trend over time.

    You can get a cheap body tape measure or caliper and use some simple calculations to give a different estimate. These are also inaccurate, but I use the body tape once a week and three of the common formulas (Navy, YMCA, Modified YMCA). Excel makes that very easy. Again, inaccurate, but they tend to trend well.

    My Eat Smart scale also has a BF% function, it trends about 5% lower than the body tape calculations.

    There are bioimpedance scales made for clinical settings that are more accurate, but they still can't match hydrostatic or DEXA scans for accuracy.

    I understand consistently inaccurate, although mine simply seems locked no matter what. For example, when I was 268 lbs, my body fat percentage was slightly over 23%. Now that I weigh 242 lbs, my body fat percentage is about 22.5%, eventhough I've lost inches, and visually see MUCH less fat on my body.

    Pretty sure I've lost more than 1% body fat LOL.

    I think it's just a hoax. Just wanted to see what others on here thought. I also have a feeling that "body type" plays a role.
  • drewlfitness
    drewlfitness Posts: 114 Member
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    heybales wrote: »
    Consumer Reports used to test them years back - the methods by which they work haven't change since.
    But they stopped because accuracy was just too bad in general.

    The could be upwards of 5% accurate, if a properly hydrated body was presented. But normally around 10%. Obviously could be worse too.

    But you'd never know if yours was, without a comparison.

    They did find some that were at least consistent. So accuracy may have been off, but at least they would show you a trend one way or another because it was always inaccurate by same amount. Others could bounce around in that 5-10% accuracy so you could go months without knowing something was actually happening.

    You do need valid weigh-in, just like normal, to minimize known expected water weight fluctuations.
    Morning after rest day eating normal sodium levels, not sore from last workout.

    Anything else is just noise.

    Also, since most are only feet based, path of measurement is up one leg and right down the other.
    Electricity and path of least resistance, right. Rest of your body is unknown. Tables are built for the stats it has, what it does see, and assumptions are made.
    Hence the reason you'll find scales that have athlete mode.
    Or have feet and hand sensors to get a 3 way cross look.

    Didn't realize that weighing yourself while your muscles are sore for example from a previous day of lifting affected the measurement. Good to know.
  • drewlfitness
    drewlfitness Posts: 114 Member
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    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    Also are you serious that you don't think you can gain muscle when operating under a deficit? That's entirely wrong from what I've read. The main important thing to gaining muscle is eating the correct macro setup, AND just as important, giving your body sufficient recovery time.

    Some people think that to gain muscle, you need to basically fatten up while lifting heavy, but that's a very extreme way of going about it in my opinion.
  • juggernaut1974
    juggernaut1974 Posts: 6,212 Member
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    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    Also are you serious that you don't think you can gain muscle when operating under a deficit? That's entirely wrong from what I've read. The main important thing to gaining muscle is eating the correct macro setup, AND just as important, giving your body sufficient recovery time.

    Some people think that to gain muscle, you need to basically fatten up while lifting heavy, but that's a very extreme way of going about it in my opinion.

    Generally speaking, you can't build significant muscle at a deficit. You can't build something from nothing.

    If your body is having to eat into your stored energy (fat & muscle) just to function (ie - caloric deficit), what the heck is it going to build new muscle from?

  • drewlfitness
    drewlfitness Posts: 114 Member
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    senecarr wrote: »
    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    I'm not new to weight lifting. I've lost 25 lbs, but my shirts are basically tighter in shoulders, pictorial area, and my back and traps have larger muscles. If I've lost 25 lbs, but my shirts are either the same or tighter, then what would you conclude?

    Also, I add calories back from exercise. I burn around 800 calories a day at the gym from lifting and cardio, and I add roughly 75% back. This means that I typically consume 2800 calories a day, eventhough my starting goal was 2200. I'm 6'1", 242lbs. I am fairly certain that my body builds muscle quicker/easier than average males.

    242 lb now, so you were 267 lb? I wouldn't put it out of the realm of possibilities you gained some muscle mass.
    I'm assuming your main lifts went up in volume?

    Yes, bench, rows, biceps, triceps, shoulders...I can lift much more weight now on all those lifts, when doing 4-5 sets of 10 reps each.
  • bpetrosky
    bpetrosky Posts: 3,911 Member
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    Here's a point of comparison. I've been doing tape measure calculations since 5/6. I also have my scale logs (Eat Smart) for the same period. I'm using the average of Navy, YMCA, and Modified YMCA calculations here.

    5/6: Tape 36.7% Scale 29.7%
    6/7: Tape 33.4% Scale 27.8%

    Delta: Tape -3.3% Scale -1.9%

    The tape measurement for 5/6 is probably inflated. For some reason my waist measurement seems higher than it should have been on that day, but I don't have enough datapoints yet to smooth it all out.

    Either way, both show the trend in the right direction for me. When I get some time I might go do the hydrostatic test and see if I can get a "correction factor" to put into this data.
  • Sued0nim
    Sued0nim Posts: 17,456 Member
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    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    Also are you serious that you don't think you can gain muscle when operating under a deficit? That's entirely wrong from what I've read. The main important thing to gaining muscle is eating the correct macro setup, AND just as important, giving your body sufficient recovery time.

    Some people think that to gain muscle, you need to basically fatten up while lifting heavy, but that's a very extreme way of going about it in my opinion.

    Yes I'm serious, apart from some outliers such as noobs and teenage boys it is very difficult to gain muscle mass in a calorie defecit. You can certainly gain strength though

    If you're thinking of recomposition then you would be eating near or close to maintenance as you follow your progressive lifting programme and that again would take a long time

    The "some people" you refer to are talking of bulking and cutting cycles which is a very standard way of going about it

    Anyway you're clearly on the right path, losing body fat and lifting to preserve LBM whilst eating in a defecit and ensuring you hit your protein and fat macros as minimums
  • Sued0nim
    Sued0nim Posts: 17,456 Member
    Options
    heybales wrote: »
    Consumer Reports used to test them years back - the methods by which they work haven't change since.
    But they stopped because accuracy was just too bad in general.

    The could be upwards of 5% accurate, if a properly hydrated body was presented. But normally around 10%. Obviously could be worse too.

    But you'd never know if yours was, without a comparison.

    They did find some that were at least consistent. So accuracy may have been off, but at least they would show you a trend one way or another because it was always inaccurate by same amount. Others could bounce around in that 5-10% accuracy so you could go months without knowing something was actually happening.

    You do need valid weigh-in, just like normal, to minimize known expected water weight fluctuations.
    Morning after rest day eating normal sodium levels, not sore from last workout.

    Anything else is just noise.

    Also, since most are only feet based, path of measurement is up one leg and right down the other.
    Electricity and path of least resistance, right. Rest of your body is unknown. Tables are built for the stats it has, what it does see, and assumptions are made.
    Hence the reason you'll find scales that have athlete mode.
    Or have feet and hand sensors to get a 3 way cross look.

    Didn't realize that weighing yourself while your muscles are sore for example from a previous day of lifting affected the measurement. Good to know.

    DOMS entails a lot of water retention for muscle repair
  • drewlfitness
    drewlfitness Posts: 114 Member
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    ceoverturf wrote: »
    rabbitjb wrote: »
    Are you new to lifting because you won't really be gaining muscle mass in a defecit

    And none if the scales can be believed as absolute numbers ...but you can use them to track relative progress over months

    Well done on your progress

    Also are you serious that you don't think you can gain muscle when operating under a deficit? That's entirely wrong from what I've read. The main important thing to gaining muscle is eating the correct macro setup, AND just as important, giving your body sufficient recovery time.

    Some people think that to gain muscle, you need to basically fatten up while lifting heavy, but that's a very extreme way of going about it in my opinion.

    Generally speaking, you can't build significant muscle at a deficit. You can't build something from nothing.

    If your body is having to eat into your stored energy (fat & muscle) just to function (ie - caloric deficit), what the heck is it going to build new muscle from?

    Point taken, so wound you say that eventhough I'm able to lift quite a bit more weight, I haven't actually added muscle? In other words, I'm stronger, with about the same muscle mass as before my last 25 lbs weight loss?

    Truly an honest question. I never thought about actually becoming stronger, by either adding no muscle mass, or by only adding slight muscle mass.

    I have seen some visually "small" guys lifting pretty heavy weight before though...