BMI seems like a wrong/bad goal?
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SingRunTing wrote: »dopeysmelly wrote: »I found BMI to be a great way to set my target weight initially. I just chose a BMI pretty much slap-bang in the middle of healthy (21.5) and as I got closer to it, just looked at myself in the mirror in a number of different settings (home, gym, fitting room) until I thought I looked OK in terms of how lean I was and acceptable amount of flabby bits. I also used waist/height ratio and also waist/hip ratio.
The combination of BMI and measurement ratios is a form of body fat measurement without the hassle IMO.
It seems to me that too many folks worry about being outliers, when by definition they're more likely just to be a regular person for the purposes of BMI.
This is what I did. I've chosen a goal weight on the higher end of a normal BMI and will reassess as I get closer. The thinnest I've ever been is at the border of overweight/obese and I have no clue what I'll look like at lower weights. I don't expect myself to be an outlier like a lot of people seem to think.
This is why I used BMI also. I didn't know what I'd look like at a healthy BMI, and I look MUCH better in the middle of healthy BMI than at the higher end. I look in the mirror and think "This is how my body is supposed to be".
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BMI seems to be directed towards a sedentary person. It is way off for athletes.0
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BMI seems to be directed towards a sedentary person. It is way off for athletes.
What kind of athlete are you referring too? A professional football player with extraordinarily above average muscle mass or a weekend warrior runner? Not all "athletes" are created equal, and there is a huge variation in muscle mass even among semi and professional athletes depending on their sport.0 -
Iwishyouwell wrote: »WalkingAlong wrote: »75% the measures agreed.
That's the thing - for most people, most of the time, BMI is a pretty good proxy. It's interesting to see some of the same people mocking others over non-belief in CICO proclaiming themselves special snowflakes when it comes to BMI.
Yes, it is very interesting how on a board that features so much collective mocking over "special snowflake" status (and often rightfully so), suddenly when discussions arise about non-fat weight ranges so many snowflakes suddenly drift down from above.
And yet, interestingly enough, 50 or so years ago the average person had no problem falling within the normal category in the very generous BMI range. Nowadays, however, it's all BS and so many claim to be outliers.
to be fair, there are probably more outliers on this site than you would normally find in your day to day...there are a lot of fitness buffs on this site.
I'm nothing special, but I'm 15%-17% BF with a BMI of 26.8. My ultimate goal is to get to a BMI of 24.9, the highest end of "normal", which would put me at about 173 Lbs and a rockin' 10% BF.
I'm just a normal dude that likes to work hard and I know for a fact there are more fit individuals than myself on this site...so it would stand to reason to me that there are probably more outliers here than you would generally find elsewhere.
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I went by BMI when I set about losing my weight. Judge for yourself but I feel like it was spot on for me. Ok I understand I am not an athlete or a body builder (pregnant or adolescent), but I can easily swim a mile or walk for 10 miles. At 46 this is a result for me. Current BMI 23.8
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WalkingAlong wrote: »This is a cool chart. I wish it included women. It says about 17% of the men were deemed overweight by BMI but not by BF%. But about 8% were the opposite-- Ok by BMI but overweight by BF%. 75% the measures agreed.
That is very cool. Any idea who made it?0 -
cwolfman13 wrote: »Iwishyouwell wrote: »WalkingAlong wrote: »75% the measures agreed.
That's the thing - for most people, most of the time, BMI is a pretty good proxy. It's interesting to see some of the same people mocking others over non-belief in CICO proclaiming themselves special snowflakes when it comes to BMI.
Yes, it is very interesting how on a board that features so much collective mocking over "special snowflake" status (and often rightfully so), suddenly when discussions arise about non-fat weight ranges so many snowflakes suddenly drift down from above.
And yet, interestingly enough, 50 or so years ago the average person had no problem falling within the normal category in the very generous BMI range. Nowadays, however, it's all BS and so many claim to be outliers.
to be fair, there are probably more outliers on this site than you would normally find in your day to day...there are a lot of fitness buffs on this site.
I'm nothing special, but I'm 15%-17% BF with a BMI of 26.8. My ultimate goal is to get to a BMI of 24.9, the highest end of "normal", which would put me at about 173 Lbs and a rockin' 10% BF.
I'm just a normal dude that likes to work hard and I know for a fact there are more fit individuals than myself on this site...so it would stand to reason to me that there are probably more outliers here than you would generally find elsewhere.
Plus a thread like this is self selecting. It's more likely to draw in people that have a reason to add something to the conversation based on their own experience. I'm definitely not an outlier at the upper range. I'm down around 18.5 and it's completely normal and healthy for me, but I can see very clearly that it isn't right for other body types. People do have different body types. It's not a special snowflake.
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No, I plucked it from the Wikipedia page on BMI. The NHANES study is cited there but I don't see that exact chart in it. I'd love to see the same chart for females.WalkingAlong wrote: »This is a cool chart. I wish it included women. It says about 17% of the men were deemed overweight by BMI but not by BF%. But about 8% were the opposite-- Ok by BMI but overweight by BF%. 75% the measures agreed.
That is very cool. Any idea who made it?
The study says BMI does well at ruling out obesity but poorly at detecting it when it exists.
"A BMI ≥ 30 had a high specificity (95% in men and 99% in women), but a poor sensitivity (36% and 49 %, respectively) to detect BF %-defined obesity. "
I believe that means what we've seen posted here before-- You're more likely to be obese by body fat and not by BMI than the opposite.
The opposite is what we see warned of here all the time-- "BMI says I'm obese but I'm not." That would be poor specificity, right? Though 5% is quite a lot and perhaps those men are more likely to be on a calorie counting site.
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WalkingAlong wrote: »75% the measures agreed.
That's the thing - for most people, most of the time, BMI is a pretty good proxy. It's interesting to see some of the same people mocking others over non-belief in CICO proclaiming themselves special snowflakes when it comes to BMI.
EXCELLENT POINT0 -
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Iwishyouwell wrote: »WalkingAlong wrote: »75% the measures agreed.
That's the thing - for most people, most of the time, BMI is a pretty good proxy. It's interesting to see some of the same people mocking others over non-belief in CICO proclaiming themselves special snowflakes when it comes to BMI.
Yes, it is very interesting how on a board that features so much collective mocking over "special snowflake" status (and often rightfully so), suddenly when discussions arise about non-fat weight ranges so many snowflakes suddenly drift down from above.
And yet, interestingly enough, 50 or so years ago the average person had no problem falling within the normal category in the very generous BMI range. Nowadays, however, it's all BS and so many claim to be outliers.
Actually, it's not terribly unusual for a man with significant muscle development to be a good BF% and yet above 25 on the BMI scale. It's more unusual for a woman, but if one is significantly overweight, one probably does have more muscle on average than someone who is not. What that means is that you may well have sufficient muscle that you'd have a quite low BF% at 25, assuming you didn't lose any.
Of course, you will lose some and your BF% estimate could well be off (mine probably was when I was at my fattest), so like most problems I suspect this one takes care of itself, if people just set a tentative goal weight and see how they feel.
It's also probably true that people today are heavy enough on average that we have screwed up perceptions. I know how I felt at 140 (BMI 25), and it was a lot thinner than I had at 140 back the first time I hit that weight, in 2000 or so (when I'd thought it was enormous). I suspect that's because even in my thinner-than-the-average-for-the-US circles being a BMI of 25 is pretty average.
That said, it's easy enough to find out if you really are a special snowflake (some are, after all), just get your body fat tested. Or don't worry about it, it's probably not really a risk to have a BMI of 26 or 27, assuming your waist measurement is good and you are fit.
Personally, I know I look best closer to a BMI of 20-21, at least unless I manage to gain more muscle, so I don't have to worry about it.0 -
Being an average person a normal BMI seems reasonable goal to me. Right now, 50 lbs. away and 65 lbs. lighter than I was 11 months ago I'm not worried about it. I'm 6 ft 2 inches and am going to look pretty good dressed at 210 - 20 lbs overweight. 185, 15 lbs less than max normal, is my longer range goal. I'm not a doctor and there's no reason for me to conclude that extra muscle mass isn't detrimental to ones body in some of the same ways (of course not all ways) as extra fat mass.0
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JenniDaisy wrote: »Just because you don't believe in BMI other people will stop believing in it, there's a reason the chart is in use.
Be prepared to have your Dr., insurance company, etc. bother you to get down to a healthy BMI.
BMI is effective for measuring populations but not individuals. Your insurance company stays in business because it focuses on populations rather than individuals.
You are not a population; you are an individual. Pay attention of BF% and disregard BMI.
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Since BF scales are about worthless and calipers are pretty iffy as well, how do you propose people monitor their body fat percent? Get a dexa scan quarterly?xmichaelyx wrote: »JenniDaisy wrote: »Just because you don't believe in BMI other people will stop believing in it, there's a reason the chart is in use.
Be prepared to have your Dr., insurance company, etc. bother you to get down to a healthy BMI.
BMI is effective for measuring populations but not individuals. Your insurance company stays in business because it focuses on populations rather than individuals.
You are not a population; you are an individual. Pay attention of BF% and disregard BMI.
If 5% of males are told they're overweight by BMI when they're not, that means 19 out of 20 are told they're overweight by BMI when they are. To me, that's pretty predictive. For women, it's 99%. I think I'll save that money and skip the dexa scans.
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BMI is a good starting point. Then you should use skinfold calipers and looking in the mirror to determine how accurate it is for you. I would assume that most people would still see themselves as leaner than their BMI, though, regardless of the facts.
Most people will (due to the law of averages) fall pretty close to their measured BMI range. There are definitely some people, though, that will not.
My BMI is around 28, but by every attempt to get an accurate body fat percentage using various caliper readings at different points and visual inspection, I'm somewhere around 18-19% body fat. The bodyfat scales put me around 22%, which is more than the calipers say, but still quite a bit below the BMI estimate. The scale only measures through my legs and most of my muscle mass is mid and upper body. My doctor knows I'm in good shape with all the lab tests to prove it, but he still has to justify it to the HMO that sees me as overweight and a candidate for increased health risks.
"Skinny fat" people are the other extreme with good BMI numbers, but extremely low muscle mass. The HMOs give them a pass on BMI, though, and only see them as unhealthy if thier lab tests suggest something not quitre right.0 -
WalkingAlong wrote: »
Since BF scales are about worthless and calipers are pretty iffy as well, how do you propose people monitor their body fat percent? Get a dexa scan quarterly?xmichaelyx wrote: »JenniDaisy wrote: »Just because you don't believe in BMI other people will stop believing in it, there's a reason the chart is in use.
Be prepared to have your Dr., insurance company, etc. bother you to get down to a healthy BMI.
BMI is effective for measuring populations but not individuals. Your insurance company stays in business because it focuses on populations rather than individuals.
You are not a population; you are an individual. Pay attention of BF% and disregard BMI.
If 5% of males are told they're overweight by BMI when they're not, that means 19 out of 20 are told they're overweight by BMI when they are. To me, that's pretty predictive. For women, it's 99%. I think I'll save that money and skip the dexa scans.
Where are those figures from?
That scatter chart posted above (if a big enough sample to extrapolate to population levels) shows 17% of males are good on body fat but overweight by BMI, so surely it's closer to correct for 15 out of 20
It also says 8% were the opposite
So in total 25% of the sample's BMI did not accurately reflect health by body fat % ...that's huge when talking about population of males
Add to that that women have higher levels of acceptable body fat % so the figures for incorrect by BMI would be higher
I'd also think that more MFP women lift heavy compared to population
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WalkingAlong wrote: »Since BF scales are about worthless and calipers are pretty iffy as well, how do you propose people monitor their body fat percent? Get a dexa scan quarterly?
A close enough way for me is to just compare myself to known body fat percentage photos online.0 -
They're from the link/excerpt in my post marked 3:59pm, which is supposedly the same study the scatter chart data came from. I think the difference is the scatter chart is referring to 'overweight' BMI and the other to 'obese'? It's confusing and I worded that later post poorly. Is it that BMI accurately predicts 'obesity' for 95% of men and 99% of women, but only 'overweight' status for 75% of men (scatter chart, and 8% of those are overweight but BMI says they're not)? That would make sense.WalkingAlong wrote: »
Since BF scales are about worthless and calipers are pretty iffy as well, how do you propose people monitor their body fat percent? Get a dexa scan quarterly?xmichaelyx wrote: »JenniDaisy wrote: »Just because you don't believe in BMI other people will stop believing in it, there's a reason the chart is in use.
Be prepared to have your Dr., insurance company, etc. bother you to get down to a healthy BMI.
BMI is effective for measuring populations but not individuals. Your insurance company stays in business because it focuses on populations rather than individuals.
You are not a population; you are an individual. Pay attention of BF% and disregard BMI.
If 5% of males are told they're overweight by BMI when they're not, that means 19 out of 20 are told they're overweight by BMI when they are. To me, that's pretty predictive. For women, it's 99%. I think I'll save that money and skip the dexa scans.
Where are those figures from?
That scatter chart posted above (if a big enough sample to extrapolate to population levels) shows 17% of males are good on body fat but overweight by BMI, so surely it's closer to correct for 15 out of 20
It also says 8% were the opposite
So in total 25% of the sample's BMI did not accurately reflect health by body fat % ...that's huge when talking about population of males
Add to that that women have higher levels of acceptable body fat % so the figures for incorrect by BMI would be higher
I'd also think that more MFP women lift heavy compared to population
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BMI is a good starting point. Then you should use skinfold calipers and looking in the mirror to determine how accurate it is for you. I would assume that most people would still see themselves as leaner than their BMI, though, regardless of the facts.
Most people will (due to the law of averages) fall pretty close to their measured BMI range. There are definitely some people, though, that will not.
My BMI is around 28, but by every attempt to get an accurate body fat percentage using various caliper readings at different points and visual inspection, I'm somewhere around 18-19% body fat. The bodyfat scales put me around 22%, which is more than the calipers say, but still quite a bit below the BMI estimate. The scale only measures through my legs and most of my muscle mass is mid and upper body. My doctor knows I'm in good shape with all the lab tests to prove it, but he still has to justify it to the HMO that sees me as overweight and a candidate for increased health risks.
"Skinny fat" people are the other extreme with good BMI numbers, but extremely low muscle mass. The HMOs give them a pass on BMI, though, and only see them as unhealthy if thier lab tests suggest something not quitre right.
so, you're saying that "most" people will view themselves as leaner than their bmi and are wrong, but you are right to view yourself as leaner than your bmi?
i hate the term "skinny fat". you can't be just skinny these days without muscle tone because people came up with a new word to insult you.
btw, I don't view myself as leaner than my BMI, but I'm just one person.
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