BMI

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Arthur Dent
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Re: BMI

Post by Arthur Dent »

Michael wrote:
CardsofSTL wrote:When I got out of Boot Camp I was a lean mean fighting machine but my BMI listed me as 22 pounds overweight. It is not a great measurement for a lot of people based on their bone structure; etc. When I am dead and buried 94 years from now you can check my skeleton's BMI and it will probably still be obese.
While people do have different body types the concept of "big boned" is largely a myth people use to justify being overweight.

In the past 50 years obesity rates (BMI measure) in America have exploded and has nothing to do with issues with the BMI measurement. I think one issue is our population is so fat people get a skewed perspective of what healthy weight actually looks like. BMI is a pretty good measure for the vast majority of the population and is an easy way to help identify health risks.

I'm speaking as someone who is overweight, but most Americans would identify as normal and healthy looking (6 ft @ 202 pounds). Despite what society thinks, there's no question I need to slim down.
While I'm sure BMI complaints are largely excuse making and that there's little issue with using it to look at trends like the fattening of America, I do wonder whether the height scaling is correct. For example, the indicated lower end of normal weight BMI (18.5) at 6 ft would be 137 pounds. That seems extremely low to me. Would losing 65 pounds actually be healthy?

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Re: BMI

Post by Michael »

I think it would be fine. In high school I was 6 ft and around 140 pounds. I was very thin, but I don't think I was unhealthy.

My wife is a couple of pounds below healthy BMI and doesn't look sick or anything. She is adding more ice cream to her diet, however. :)

Arthur Dent
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Re: BMI

Post by Arthur Dent »

Hmmm. I don't remember what my weight was in high school, but in college I think I was ~185 at 6'3" and at the time I felt I that was too thin while BMI thinks I could have dropped another 35 pounds or so. Maybe that'd be fine, but I remain skeptical.

Reading a bit more, it seems like my skepticism would be better directed at the cut-offs rather than the height scaling. Even as far back as the 1923, median BMI was ~24 meaning that even then almost half the population would be considered overweight. This seems like an awfully idealist framework for looking at the weight problem. And it also appears BMI correlates poorly with body fat percentage, which would suggest that applying it literally on an individual rather than population level may be misleading:

The relatively poor correlation between percent of body fat mass and BMI also clearly has been shown more recently in the NHANES III database in which bioelectrical impedance was used to estimate the fat component of body composition.51 In subjects with a BMI of 25 kg/m2, the percent of body fat in men varied between 14% and 35%, and in women it varied between 26% and 43%. Thus, using the NIH-suggested criterion based on percent of body fat to define obesity, subjects with a BMI of 25, a group that would be considered to be essentially normal, were associated with a body fat mass that varied again between low normal to obese. Also it is of interest that in the entire NHANES cohort, the BMI correlated better with lean body mass than with fat mass in men.51 More recent NHANES data also indicate a poor correlation of BMI with percent of body fat, particularly in men.58

Anyway, BMI and I currently agree that I should lose some weight if not the precise amount.

And while I don't know whether BMI is a particularly good personal health statistic, that is neither here nor there to the general point that our diets are generally not great and we aren't getting enough exercise.

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haltz
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Re: BMI

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AWvsCBsteeeerike3 wrote:
haltz wrote:
I made a bet recently that I could do the carnivore diet for a month. I'm 8 days in and I hate it. I haven't gotten over any hump and feel like dog [expletive] at several points during the day. I think I might go vegetarian after this. Just the smell of bacon or a ribeye makes me want to puke.
Just googled carnivore diet. Wow. Good luck. Keep us posted.
It's so stupid. I can't wait until it's over.

I'm strongly considering bailing on the whole thing. I feel lethargic and I'm not sleeping. I have too much going on right now to operate this way. Maybe I'm doing something wrong or this is just a diet for crazy people and liars.

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lukethedrifter
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Re: BMI

Post by lukethedrifter »

Lions don’t sleep at night either. Just sayin’.

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Donnie Ebert
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Re: BMI

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AWvsCBsteeeerike3
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Re: BMI

Post by AWvsCBsteeeerike3 »

haltz wrote:
AWvsCBsteeeerike3 wrote:
haltz wrote:
I made a bet recently that I could do the carnivore diet for a month. I'm 8 days in and I hate it. I haven't gotten over any hump and feel like dog [expletive] at several points during the day. I think I might go vegetarian after this. Just the smell of bacon or a ribeye makes me want to puke.
Just googled carnivore diet. Wow. Good luck. Keep us posted.
It's so stupid. I can't wait until it's over.

I'm strongly considering bailing on the whole thing. I feel lethargic and I'm not sleeping. I have too much going on right now to operate this way. Maybe I'm doing something wrong or this is just a diet for crazy people and liars.
I'd guess the later.

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Re: BMI

Post by Michael »

Arthur Dent wrote:Hmmm. I don't remember what my weight was in high school, but in college I think I was ~185 at 6'3" and at the time I felt I that was too thin while BMI thinks I could have dropped another 35 pounds or so. Maybe that'd be fine, but I remain skeptical.

Reading a bit more, it seems like my skepticism would be better directed at the cut-offs rather than the height scaling. Even as far back as the 1923, median BMI was ~24 meaning that even then almost half the population would be considered overweight. This seems like an awfully idealist framework for looking at the weight problem. And it also appears BMI correlates poorly with body fat percentage, which would suggest that applying it literally on an individual rather than population level may be misleading:

The relatively poor correlation between percent of body fat mass and BMI also clearly has been shown more recently in the NHANES III database in which bioelectrical impedance was used to estimate the fat component of body composition.51 In subjects with a BMI of 25 kg/m2, the percent of body fat in men varied between 14% and 35%, and in women it varied between 26% and 43%. Thus, using the NIH-suggested criterion based on percent of body fat to define obesity, subjects with a BMI of 25, a group that would be considered to be essentially normal, were associated with a body fat mass that varied again between low normal to obese. Also it is of interest that in the entire NHANES cohort, the BMI correlated better with lean body mass than with fat mass in men.51 More recent NHANES data also indicate a poor correlation of BMI with percent of body fat, particularly in men.58

Anyway, BMI and I currently agree that I should lose some weight if not the precise amount.

And while I don't know whether BMI is a particularly good personal health statistic, that is neither here nor there to the general point that our diets are generally not great and we aren't getting enough exercise.
I think you're mainly highlighting fair BMI criticisms that tends to be on the margins. However, for the vast majority of people BMI is an effective way to help determine probabilities for future health outcomes, not what's considered "normal" for whatever time period we're discussing. I think the weight ranges are fairly wide to account for the differences in our makeups.

This isn't a perfect analogy, but I'd liken BMI to the baseball stat OPS. In my opinion, OPS is a simple and easy to calculate statistic that effectively communicates a hitters worth. Today we have better advanced stats, but OPS is pretty darn good shorthand that highly correlates with those advanced stats. Sure, with OPS certain players will be undervalued/overvalued, but for the vast majority of situations it's not worth obsessing over and it doesn't make OPS a junk stat. OPS is a statistic I tend to use when I'm discussing baseball with less hardcore fans, much like BMI is a measure doctors use with patients who aren't health enthusiasts.

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JCShutout
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Re: BMI

Post by JCShutout »

haltz wrote:
AWvsCBsteeeerike3 wrote:
haltz wrote:
I made a bet recently that I could do the carnivore diet for a month. I'm 8 days in and I hate it. I haven't gotten over any hump and feel like dog [expletive] at several points during the day. I think I might go vegetarian after this. Just the smell of bacon or a ribeye makes me want to puke.
Just googled carnivore diet. Wow. Good luck. Keep us posted.
It's so stupid. I can't wait until it's over.

I'm strongly considering bailing on the whole thing. I feel lethargic and I'm not sleeping. I have too much going on right now to operate this way. Maybe I'm doing something wrong or this is just a diet for crazy people and liars.
I'd never heard of the carnivore diet. It sounds terrible. Unless you're eating animal organs and blubber you aren't getting the vitamins and nutrients you need from vegetables and fruit. Of course you feel like crap. You need vitamins and stuff.

And I'm doing keto right now, so I'm a believer in low carb diets, but still, veggies man. They're like, good for you.

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lukethedrifter
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Re: BMI

Post by lukethedrifter »

I honestly believe that the keto diet is gonna have some long range negative effects of dieters. Too bad we couldn’t learn to just minimize sugar and processed foods; eat carbs etc in moderation. It’s like humans can’t just make reasonable adjustments, they have to bottom out then find a new religion. I guess the structure is easier.

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