So, you think you hate the BMI now?

I thought this was about the 'new BMI' calculator

http://people.maths.ox.ac.uk/trefethen/bmi_calc.html

I thought this was about the 'new BMI' calculator

http://people.maths.ox.ac.uk/trefethen/bmi_calc.html

Haha no. That would be news from this year. This thread is about an article published in April of last year.

The concern of the article and base study is false negatives - people with "normal" BMI but "obese" body fat levels. Those people are passing under the radar. Reducing the BMI cutoff in the manner suggested would enable detection the false negatives. But obviously it would pick up a lot more false positives, which is why the suggested BMI change probably won't happen.

But the main point of the study cited by the article was that BMI isn't accurate in obesity detection, and doctors should incorporate body fat testing. The study results suggest leptin testing as a reliable alternative when DXA scan testing is unavailable as an option.

http://www.ncbi.nlm.nih.gov/pubmed/22485140

I refuse to use BMI. It's not a healthy way to measure people. Everyone is different, we all have different muscle and fat content. Therefore, they need to readjust everything with correct measurements. sigh!!!

But, I thought a BMI from 18.5-25 was considered healthy? WTF if a woman has a BMI of like 24.5 they go from being in the healthy range to obese range? That's ridiculous. :explode:

While I agree that body fat percentage is s much better metric to track, it is also much harder for the general population to have accurately measured.

BMI is easily calculated and is a useful metric. Yes it is not reliable for body builders or football players but those groups are a very small percentage of the general population.

I say this as someone who carefully tracks his body fat, cholesterol and blood pressure. BMI is but perfect but it is useful for the general population most of which (in the US) is currently overweight or obese.

It's not really useful for ANYONE who is athletic and carries a lot of muscle mass... I am a volleyball player with very muscular legs and shoulders all the time... given that I would like to lose 10-15 more lbs, I'm still considered obese by the BMI standards though I wear a size 8 or 10 in pants. My doctor did body fat on me and I am in the healthy range.

That is completely nuts. We already have a standard for being overweight that is much lower than the World Health Organization standard. A BMI of 24 shouldn't even be considered overweight, let alone obese. It sounds like they want to instill panic. Either we should use body fat percentage to set standards, leave the standard the way it is, or raise it a few BMI points.

Our company told us that starting in 2015, BMI will be a factor in our healthcare plan cost (as will smoking). I can see this becoming a popular trend among healthcare companies.

It all makes perfect sense now. More obese people means insurance companies can charge more.

That's a load of rubbish. My BMI was 27 when I first starting using MFP and I honestly was not THAT big.

I hear that under Obamacare BMI may be use to determine if you are obese for your rates. Love the govt.

God I love the National Health Servicevin the UK.

You should sure it's still beaurcracy, but at least it's not the cluster f-ck we have in the US.

The affordable care act is an insurance exchange though, so you'd still be purchasing insurance from individual plans and/or Medicaid/medicare and if those require BMI...

Anyways, I'm seriously confused to this article what is the thinking with lowering the threshold, so people will get educated? Didn't see any correlation to heart disease or diabetes. Of course there is no relation to body fatness and BMI, BMI is just a ratio of height to weight!!! Duh! If it needs to be that revised why the flying fig are we using it? Let's just go back to Hamwi IBW if it's that tenuous...I swear.

People look at BMI backwards.

- It isn't a useful tool to identify if you fat.
- It is a useful tool to identify if you are not fat.

If you are looking at a large group of people and what to separate them into two groups, fat and not fat, BMI is the easiest and quickest tool that will allow you to identify the vast majority of not fat people with high confidence. BMI will leave a lot of false positives in the fat group, but very, very few false negatives in the not fat group (further decreasing the false negatives is what the article gets at). The false positives can be removed from the fat group, but any measurement is going to be more complicated, time consuming, and expensive to make; it doesn't make any sense whatsoever to do a more advanced measurement on everybody, just do it on those that might be false positives.

Why manually clear your whole email inbox when junk mail filters can do most of the heavy lifting? Applying BMI to a population is basically the same thing as a junk mail filter. It will identify the vast majority of people that aren't fat. Some junk mail will still get through though; BMI will fail to identify some people that are not fat.

25 has never been healthy, it was always the start of being overweight

24.9 is healthy. 25 is overweight. That's a difference of about .1 lbs for my height (145.3 vs. 145.4)

Go from overweight to healthy with one emptying of the bladder! MAGIC! LOL

People look at BMI backwards.

- It isn't a useful tool to identify if you fat.
- It is a useful tool to identify if you are not fat.

If you are looking at a large group of people and what to separate them into two groups, fat and not fat, BMI is the easiest and quickest tool that will allow you to identify the vast majority of not fat people with high confidence. BMI will leave a lot of false positives in the fat group, but very, very few false negatives in the not fat group (further decreasing the false negatives is what the article gets at). The false positives can be removed from the fat group, but any measurement is going to be more complicated, time consuming, and expensive to make; it doesn't make any sense whatsoever to do a more advanced measurement on everybody, just do it on those that might be false positives.

Why manually clear your whole email inbox when junk mail filters can do most of the heavy lifting? Applying BMI to a population is basically the same thing as a junk mail filter. It will identify the vast majority of people that aren't fat. Some junk mail will still get through though; BMI will fail to identify some people that are not fat.

but here's the thing... why are they focusing on "fat" and "not fat"?
We can generally visually judge if someone is too large for their height, but the real question is: is this person's body HEALTHY?

The military goes by BMI, when I joined in 2001 I had to get a waiver for my weight because I weighed 182, and the government felt I should weigh 172 max. At that point in my life I was running, swimming and lifting 5-6 days a week, and had a BF% between 12-15% I had to get taped before every PRT because I was considered overweight. Made no sense to me. BMI is a useless one size fits all government classification, and is just one more example of why the government shouldn't be trusted with even the power it already has over us, let alone any more.

Rigger

So?

Its either that or use the tape on everybody.

It worked exactly as intended, quickly separate out a group that you can say with reasonable confidence is not overweight, requiring no further effort or verification for that group.

When you need to identify who is and isn't fat, BMI is always the first used and easiest tool.

Get a grip man, it makes perfect sense why it would be used and it is a very useful classification.

but here's the thing... why are they focusing on "fat" and "not fat"?
We can generally visually judge if someone is too large for their height, but the real question is: is this person's body HEALTHY?

Whether you are or aren't fat is a factor insurance companies and employers are allowed to discriminate on. Thus ways to objectively identify who is and isn't fat is important.