Why I hate Body Fat Percentage!

Actually pictures/mirros do lie...if you stand in different lighting or angle, holding camera slight different you will look different.

Also if you were dehydrated or bloated from previous night over eating, your picture looks different too. So now I just crushed your #1 tracking method.

True!

It's no different than tracking your weight with a scale. Sure, you can look in the mirror and tell you look better, but some people like numbers. I'm one of them, as is CA_Underdog, I suspect.

The problem is that when you let the numbers define you and your self-worth, you've lost sight of the bigger picture. I suspect your bigger issue is with people that get so caught up in the actual number that they lose sight of the forest for the trees.

Honestly when people who let their appearance define their self-worth get high and mighty over people who let their scales define their self-worth it just makes me smirk a bit.

I think the idea is that both want to look good and one is using looking good as a measure while another is using a much more arbitrary number as their measure. I get the idea you should go off appearence over a scale weight but honestly both are pretty shallow means of judging self-worth.

I hear people saying: No no, don't use scale weight use bodyfat percentage! Or no, no don't use body fat percentage use appearance. Or no no don't use appearance use tape measure.

I'm just sitting here thinking to myself...why not just use all of them. Its not like you have to pick one. More data the better right?

I hear people saying: No no, don't use scale weight use bodyfat percentage! Or no, no don't use body fat percentage use appearance. Or no no don't use appearance use tape measure.

I'm just sitting here thinking to myself...why not just use all of them. Its not like you have to pick one. More data the better right?

This is really all I meant. We are all using all of these things. And none of them.

I don't think picking this one data point as completely worthless is any more valid than saying weighing yourself, or measuring yourself, or looking in the mirror, is invalid.

As long as you accept the facts (BF measurements carry a margin of error), track away.

I hear people saying: No no, don't use scale weight use bodyfat percentage! Or no, no don't use body fat percentage use appearance. Or no no don't use appearance use tape measure.

I'm just sitting here thinking to myself...why not just use all of them. Its not like you have to pick one. More data the better right?

This is what I was saying. Why not track weight, body fat, measurements, etc. Even blood work, lifting stats and mile run times are good things to track. They are all indicators of progress. Plus, with body composition it is better to have lots of data.

Good post OP.

I'll be honest, I use a handheld electrical impedance device to track body fat. I don't care about accuracy, as long as the device has somewhat decent precision.

I just care about a general trend over a long period of time and I know that different levels of hydration can influence the result.

That said, I don't really have a goal body fat percentage. And if I really cared about a somewhat more accurate figure, I'd schedule a water displacement test. But it's just one (of many) metrics for me and I just keep track of it for fun.

I think what Vismal is saying (and he can correct me if I am wrong) is not so much omg don't do this its a waste of time so much as he is saying that too many people become myopically focused on achieving the magic number of 10% or 18% and ignore other factors that are arguably more important like...how much energy do they have....how strong are they feeling....how far can they run....what is their functional strength....how do they look.

That said I think its perfectly fine to measure bodyfat percentage and have a goal in mind, just as long as you are rational enough to realize that measurements aren't 100% accurate and your goal might end up needing to shift as you learn more about your own body.

That can be said about everything. Don't focus only on scale. Don't focus only on body fat. Don't focus only on looks (this can be one of the worst). There are tons of goal posts people have in fitness or weight loss and they let those determine their worth.

Seriously...I actually like using clothes fit...but it has to be the same pair of old pants...

Tape measures can increase due to bloating or increased fat or water retention.
Scale weight can increase due to water weight or fat or lean mass or all of them.

Some people are going to obsess about anything and everything. Instead of saying they shouldn't focus on body fat (which actually is a good thing to track along with weight and measurements) you should have just said people should just stop obsessing about numbers in general. I think people should take as many data points as possible. Weight, measurements, calipers, bio electrical impedance, lifting stats, blood tests, mile times, etc.

You point out that the tests are not accurate, which I agree, but if they use the same method over and over it gives them a fairly constant trend. They might be off 5%, but they will probably always be off 5%.

But if a body fat percentage technique has a margin of error of +/- 5% then to me it's 100% worthless. So if it says 15% I could be as high as 20 which means I still have lots of fat to lose, or as low as 10 which means I have very little fat left to lose. The trends aren't reliable either meaning they are not always off by the same amount. If that were true they would have more use. I agree tape measurements and scale weights can be thrown off by water retention. But If you weigh yourself daily, and take a weekly average, comparing week to week over the course of a month, that will account for water weight swings. Scale weight would only increase due to lean mass if you were actively trying to gain lean mass, in which case, you want scale weight to go up.

if you've ever used a caliper on yourself, you know that its basically impossible to get the same % twice

I think the formula's that require you to input different tape measure measurments (while the least accurate) are by far the most consistent.

when using calipers, you have to worry about errors in the input (slightly different test sight or amount of skin you pinch will make a big difference).

Its hard to screw up a tape measurement. so changes in the % are due to actual changes in your body.

EDIT: suprised you are advocating daily weighting

But my entire point was at what point would high accuracy ever be critical?

I agree we rarely need high accuracy--consistency is plenty! Professional athletes may differ. I didn't take on the majority of your post, just your knock on BIA scales as "trash", when I've found them helpful.

At what point is knowing that number going to change anything? I bet you knew your body fat was decreasing despite that graph.

I use it in the following ways--

1. Your real body fat % doesn't change much day-to-day. A small change in body fat % gives me more confidence in a weight reading. A big change in body fat % gives me less confidence in a weight reading. In other words, this help me figure out if that weekly 4lb weight loss is "real" or simply due to water weight.

2. When you hit a weight-loss plateau, what your body fat percentage is doing can be both insightful and motivating. If your composition is improving, keep at it! Otherwise, it's time to consider modifying your plan.

3. It helps gauge the relative effectiveness of a particular fitness regimen. I've done ones where I lost weight but my body fat % remained relatively unchanged. I started a new one and I'm curious how it will compare.

I'm wondering how often people are actually compliant with all these things.
Abstain from eating and drinking within 4 hours of the test
Avoid exercising within 12 hours of the test
Void (urinate) completely prior to testing
Avoid taking diuretics prior to testing unless instructed by your physician

Weighing in the morning, after peeing, gets you most of the above.

Do not drink alcohol within 48 hours of the test

I've never found a can of beer, a glass of wine, or a light workout to impact results much. If you drink heavily, and don't replenish with water, certainly that can have a dehydrating effect and affect results! Also, I've found long endurance efforts such as marathons can influence results closer to 48 hours.

I question whether the guy making 10 bucks an hour at planet fitness is going to help create a "perfect condition".

That's one reason I prefer BIA. All the "cautions" are within my realm of control, and I can do it often enough (my scale uploads my results daily) to easily weed out any one-off statistically abnormalities.

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I think what Vismal is saying (and he can correct me if I am wrong) is not so much omg don't do this its a waste of time so much as he is saying that too many people become myopically focused on achieving the magic number of 10% or 18% and ignore other factors that are arguably more important like...how much energy do they have....how strong are they feeling....how far can they run....what is their functional strength....how do they look.

That said I think its perfectly fine to measure bodyfat percentage and have a goal in mind, just as long as you are rational enough to realize that measurements aren't 100% accurate and your goal might end up needing to shift as you learn more about your own body.

That can be said about everything. Don't focus only on scale. Don't focus only on body fat. Don't focus only on looks (this can be one of the worst). There are tons of goal posts people have in fitness or weight loss and they let those determine their worth.

Well yeah but if we distill it down like that then really the answer to every question ever posed on MFP is "Don't be dumb".

I think what Vismal is saying (and he can correct me if I am wrong) is not so much omg don't do this its a waste of time so much as he is saying that too many people become myopically focused on achieving the magic number of 10% or 18% and ignore other factors that are arguably more important like...how much energy do they have....how strong are they feeling....how far can they run....what is their functional strength....how do they look.

That said I think its perfectly fine to measure bodyfat percentage and have a goal in mind, just as long as you are rational enough to realize that measurements aren't 100% accurate and your goal might end up needing to shift as you learn more about your own body.

That can be said about everything. Don't focus only on scale. Don't focus only on body fat. Don't focus only on looks (this can be one of the worst). There are tons of goal posts people have in fitness or weight loss and they let those determine their worth.

Well yeah but if we distill it down like that then really the answer to every question ever posed on MFP is "Don't be dumb".

I've seen you ask the same question that you have previously answered for others.

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