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How do we judge a healthy weight range? BMI is no longer valid?
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I've been silently following this thread since it started. Every weight-goal/BMI thread where I've commented, I've always said, BMI is a great indicator for where someone's healthy weight should fall for a given height. There's a huge range in the normal BMI category, and most can easily fall into that range without being "overly skinny" (whatever that's supposed to mean). It should be used along with other measures, just as many in this thread have stated. The number of people on (and off) MFP who think they are exceptions to the BMI guideline is indicative not of the accuracy of the BMI guideline but of the overwhelming state of denial many people are in.
I'm someone who has been overweight/obese since childhood. I've never seen my adult body at a healthy weight, so I have no idea what I will look like once I reach my goal. At 5'7" and 173 lbs I'm still well into the overweight category. However, when I met up with my family for vacation this summer, my mother couldn't stop commenting on how "skinny" I looked. Seriously, I'm not skinny or thin by any measurement. I am smaller than she's ever seen me as an adult though, and that threw off her perception of me.
I'm currently aiming for 140 lbs for my initial goal. I fully expect to reevaluate once I'm there to determine how much more fat I can/should/want to lose. At my height, that's the middle of the normal BMI range. Had you asked me 10 years ago what I should weigh, I would have said 160 because "my frame is big." Yes, I have wide shoulders. No, I no longer think that means that I need to aim toward the top end of the normal BMI range or slightly higher. After seeing my body transform over the past year, and seeing how much further I have to go, I can fully recognize that how wide my shoulders are will have not much bearing on how much I should weigh.
I believe that there are many people who will never accept the BMI scale simply because it doesn't fit with their perceptions of aesthetics. That doesn't make the BMI scale inaccurate. A personal desire to be at a higher weight, even if you aim for high muscle mass, does not detract from the BMI guidelines. It just means that you will be abnormal, an outlier, and you'll almost certainly know it, because you'll be ripped.
Also thought I'd drop a couple links that I've found good reading on this topic:
A nice Reddit thread discussing the topic of BMI accuracy: https://reddit.com/r/fatlogic/comments/3o00s1/serious_why_isnt_bmi_accurate/
Various measures for obesity/fat %: https://hsph.harvard.edu/obesity-prevention-source/obesity-definition/how-to-measure-body-fatness/
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I'm having a hard time understanding how BMI promotes undermuscled physiques when a person with a healthy BMI can have a ridiculously athletic 5% BF right on up to a very soft 35% BF. The metric is kg/m2. BF% is not considered in the calculation whatsoever.
As an example, I am 5'4" and weigh 126lbs. This gives a BMI of 21.6. At 25% BF, I am 31.5lbs fat and 91.5 lean body mass. My goal is 20% BF but I don't really want to lose any more body weight. At my goal, I will still be a BMI of 21.6 because neither my height not weight have changed but I will be 25.2lbs of fat and 120.8lbs of lean mass instead. MY BMI WILL BE THE SAME AT 25% BF AS AT 20% BF. It will be the same at ANY BF%, providing my weight does not change, because BF% is not what is measured by BMI.
What is going on is that you don't think you will ever be within a normal BMI range and you are making excuses as to why you won't. You're worrying about having inadequate muscle mass as a health-affected obese man. AKA putting the cart in front of the horse. This is what I mean by being in denial. You're fretting that you won't look like Arnold or be muscled enough when you should be worrying about getting your body weight, regardless of your BF% or lean muscle mass, within a healthy range.
Are motor vehicles also stupid because you will never be a race car driver?16 -
bennettinfinity wrote: »I don't recall mentioning bio-impedance or DEXA scans...
Right. You asked a question, and I gave you the answer. Hopefully you understand a little better now.
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Interesting, regarding Ashley Grahm. At 5'9" and 170 pounds (according to both bodymeasurements.org and celebheightweight.com) her BMI is 25.1... barely "overweight" and not even close to "obese" if you accept BMI. Do any of you calling her fat know her actual body fat percentage? The only thing I found was a search result that linked to a "page not found." It said 33%, which would put her at the top end of healthy or the low end of over fat, depending on whose chart you're looking at.
So who has the distorted view here? The person who recognized her as being at the upper limit of a healthy composition? Or the people calling her flat out fat?2 -
Traveler120 wrote: »Usually, it's said to be inaccurate for those who're VERY muscular. The average woman is nowhere near as muscular as Serena Williams and she's 5'9" and said to be 155 lbs, BMI 22.89. She'd have to be 170 lbs to reach overweight BMI of 25+ and in her case, it would not apply coz she's so muscular. So, unless you're as muscular as she is, then yeah, BMI is a good indicator of what's a healthy weight.
I think fat acceptance and the obesity epidemic is distorting people's view of what's truly normal weight so folks start blaming the BMI indicator for being wrong, when in reality, people are just too fat.
Good call on using Serena Williams as an example! She's very muscular but knowing that she is 23 ish suggests to me that it would be very difficult indeed for a woman to out-muscle the healthy range.
Also I like knowing the stats of celebs and sports stars. Helps give reference points for what to aim at.2 -
MarkusDarwath wrote: »Interesting, regarding Ashley Grahm. At 5'9" and 170 pounds (according to both bodymeasurements.org and celebheightweight.com) her BMI is 25.1... barely "overweight" and not even close to "obese" if you accept BMI. Do any of you calling her fat know her actual body fat percentage? The only thing I found was a search result that linked to a "page not found." It said 33%, which would put her at the top end of healthy or the low end of over fat, depending on whose chart you're looking at.
So who has the distorted view here? The person who recognized her as being at the upper limit of a healthy composition? Or the people calling her flat out fat?
Ten pounds can make a notable difference, especially with how her fat is distributed. I haven't seen pictures of her at 170. All of the ones I saw appeared to be from the time frame where she was pegged at 180+.
And to use your own argument for you, BMI doesn't tell you anything about composition. I'm male, 5'10", and 150.5 lbs. I also still have a completely terrible body composition that I am currently working on, even though I fall right into the middle of the "healthy" range. So yeah, we're still right back to it being useful for a population, but not so helpful to the individual, beyond giving them an easy to understand base mark to work from.
Girl's fat, or at least was in the pictures I saw, and nothing about perception changes that.2 -
MarkusDarwath wrote: »Interesting, regarding Ashley Grahm. At 5'9" and 170 pounds (according to both bodymeasurements.org and celebheightweight.com) her BMI is 25.1... barely "overweight" and not even close to "obese" if you accept BMI. Do any of you calling her fat know her actual body fat percentage? The only thing I found was a search result that linked to a "page not found." It said 33%, which would put her at the top end of healthy or the low end of over fat, depending on whose chart you're looking at.
So who has the distorted view here? The person who recognized her as being at the upper limit of a healthy composition? Or the people calling her flat out fat?
That's because she's lost weight. She was fat (not meant as a bad word just a fact, my own goal weight is fat because that's my aesthetic preference), now she is in the upper range of normal (but definitely not "too skinny" as you call those who are in the upper range of normal).
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Similar BMI to me. We're both fat, just in different places. She probably wouldn't get away with it in her mid 40s, either.1
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amusedmonkey wrote: »MarkusDarwath wrote: »Interesting, regarding Ashley Grahm. At 5'9" and 170 pounds (according to both bodymeasurements.org and celebheightweight.com) her BMI is 25.1... barely "overweight" and not even close to "obese" if you accept BMI. Do any of you calling her fat know her actual body fat percentage? The only thing I found was a search result that linked to a "page not found." It said 33%, which would put her at the top end of healthy or the low end of over fat, depending on whose chart you're looking at.
So who has the distorted view here? The person who recognized her as being at the upper limit of a healthy composition? Or the people calling her flat out fat?
That's because she's lost weight. She was fat (not meant as a bad word just a fact, my own goal weight is fat because that's my aesthetic preference), now she is in the upper range of normal (but definitely not "too skinny" as you call those who are in the upper range of normal).
Hard to tell in that second picture, due to the jacket, but yeah, just from what you can see of the abdominal area, hands, and face, that weight loss made a pretty big difference.0 -
born_of_fire74 wrote: »I'm having a hard time understanding how BMI promotes undermuscled physiques when a person with a healthy BMI can have a ridiculously athletic 5% BF right on up to a very soft 35% BF.
Ok, let me qualify my statement. At a body fat percentage that is simultaneously healthy, attainable and desirable to most people, they would have to unnecessarily sacrifice muscle mass to get their BMI under 25. And I say unnecessarily in that there is no medical benefit to doing so.The metric is kg/m2. BF% is not considered in the calculation whatsoever.
And that is the huge flaw of BMI. It is claimed to give an estimation of fatness, yet the metric actually has nothing to do with fat. Excess fat contributes to health issues, lean mass does not. Looking at the relationship of height to weight is of no value if it cannot reasonably assess actual fat composition.
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amusedmonkey wrote: »That's because she's lost weight. She was fat (not meant as a bad word just a fact, my own goal weight is fat because that's my aesthetic preference), now she is in the upper range of normal (but definitely not "too skinny" as you call those who are in the upper range of normal).
Ok, I had not seen pictures of her prior to the advertisement in Sports Illustrated. IIRC, that was in the swimsuit issue the year before they actually put her in as a swimsuit model.
I will agree that she looks fat in the top pic. But still smokin' hot.
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To add to my previous post. I didn't say that people at the top end of "normal" BMI are categorically all too skinny. What I said was that people at an average healthy BF% quite often have to be "too skinny", meaning low muscle mass in order to also fit BMI. Apparently this applies more often to men than women, as "normal" lean muscle is higher for men.0
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MarkusDarwath wrote: »stevencloser wrote: »MarkusDarwath wrote: »stevencloser wrote: »The one that uses wrist and frame size was also said to overestimate lean mass potential.
Yes, but I highly doubt it's 50 pounds over.
Try the others and see how different it is for you.
I mentioned it previously. I did try the others and they still gave me a total weight that was over 200 pounds at 15% body fat, where the BMI charts say I would be a 24.4 at 185 pounds. When a calculation shows that I have to shed functional muscle in order to reach a level where I'm considered to border on "overweight", there is something wrong with the references being used.
You have plenty beside functional muscle to shed... You're sitting at about 35% BF currently (If your pics are current).2 -
MarkusDarwath wrote: »born_of_fire74 wrote: »I'm having a hard time understanding how BMI promotes undermuscled physiques when a person with a healthy BMI can have a ridiculously athletic 5% BF right on up to a very soft 35% BF.
Ok, let me qualify my statement. At a body fat percentage that is simultaneously healthy, attainable and desirable to most people, they would have to unnecessarily sacrifice muscle mass to get their BMI under 25. And I say unnecessarily in that there is no medical benefit to doing so.The metric is kg/m2. BF% is not considered in the calculation whatsoever.
And that is the huge flaw of BMI. It is claimed to give an estimation of fatness, yet the metric actually has nothing to do with fat. Excess fat contributes to health issues, lean mass does not. Looking at the relationship of height to weight is of no value if it cannot reasonably assess actual fat composition.
BMI is just built off insurance risk tables though. Health risk increases over (or under) a given mass for a given height. Saying that Most People can't get a medical benefit from getting under a 25 BMI is nonsensical. All BMI is saying, literally (in the original sense of the word) is that Most People do get a health benefit from getting under a 25 BMI. What it doesn't say is which people are part of that "Most People" group.
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coreyreichle wrote: »You have plenty beside functional muscle to shed... You're sitting at about 35% BF currently (If your pics are current).
My pics are 21 pounds ago at 281, I'm at 260 now, but still around 34%. To get down to a 24.4 BMI I would have to get all the way down to 185. To reach that without losing lean mass I'd have to get all the way down to 7.5 percent body fat, which I have no desire to do. To hit 185 at my goal body fat of 15%, there is no way to do it without shedding lean mass to a point where I would (continue to) have a less than average percentage of muscle mass.
Based on my present lean mass excluding muscle, to be at 15% BF and average muscle percentage (between 40 and 45% of total body weight) I need to be between 209 and 235 pounds. I choose 220.
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BMI is just built off insurance risk tables though. Health risk increases over (or under) a given mass for a given height. Saying that Most People can't get a medical benefit from getting under a 25 BMI is nonsensical. All BMI is saying, literally (in the original sense of the word) is that Most People do get a health benefit from getting under a 25 BMI. What it doesn't say is which people are part of that "Most People" group.
Statistically speaking, most people -don't- get a particular benefit from being under 25BMI. The actual cutoff for increased risk is 30 for those without other health risk indicators, or 27-28 for those who do have other indicators (such as high blood pressure, glucose or cholesterol.)
The "overweight" category has no meaning by itself.
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@MarkusDarwath I guess the only thing left to do is to wait and see what the status is when you get to 220. Since we are using bio-impendence estimations so the muscle mass measurement can be used, but loosely at this point, and we really don't know how much muscle mass you may lose while continuing to lose weight, it's kinda pointless to keep debating your stats. All I know is I wish you luck getting there, and look forward to reattacking this at that point.
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MarkusDarwath wrote: »BMI is just built off insurance risk tables though. Health risk increases over (or under) a given mass for a given height. Saying that Most People can't get a medical benefit from getting under a 25 BMI is nonsensical. All BMI is saying, literally (in the original sense of the word) is that Most People do get a health benefit from getting under a 25 BMI. What it doesn't say is which people are part of that "Most People" group.
Statistically speaking, most people -don't- get a particular benefit from being under 25BMI. The actual cutoff for increased risk is 30 for those without other health risk indicators, or 27-28 for those who do have other indicators (such as high blood pressure, glucose or cholesterol.)
The "overweight" category has no meaning by itself.
That's why, when one is in the overweight category, the general advice is either "consider doing something about it", or "just don't gain anymore". It's not until they kick down the door on obese that the advice changes to "okay, seriously, fix yourself".0
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