Welcome to Debate Club! Please be aware that this is a space for respectful debate, and that your ideas will be challenged here. Please remember to critique the argument, not the author.
How do we judge a healthy weight range? BMI is no longer valid?
Replies
-
3dogsrunning wrote: »MarkusDarwath wrote: »Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
What about those without the ability to measure BF%?
They have a scale, but not a tape measure and internet connection? Where are they looking up the BMI chart from?
0 -
rankinsect wrote: »Unless they're paying for a DEXA scan, though, or maybe a BodPod, the reality is that most methods of measuring body fat % have such a large margin of error that they are probably even less reliable than BMI as a tool to calculate goals from.
I agree there is a fairly large margin for error. I disagree that it's less reliable than BMI.
0 -
MarkusDarwath wrote: »3dogsrunning wrote: »MarkusDarwath wrote: »Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
What about those without the ability to measure BF%?
They have a scale, but not a tape measure and internet connection? Where are they looking up the BMI chart from?
The tape measure method varies widely. It is laughable. Like someone else said above, it would be much more inaccurate than BMI.
2 -
MarkusDarwath wrote: »Packerjohn wrote: »If someone just getting started is 300 pounds and the BMI says they should be 150-175, don't you think somewhere in that range is a better long term goal than pulling something out of the air?
I think they should measure or calculate their body fat percentage, use that to determine lean mass, and pick a BFP within normal range to shoot for, adding that number back to their lean mass.
Yes, they might likely lose some lean mass along the way and need to recalculate, but chances are the initial target is going to be less daunting than right off the bat deciding they have to lose half of themselves. They would at least be using solid personal numbers instead of a generic guesstimation.
Nice idea in theory. I think in fact you would find most people have no clue what BF% is, could not reasonably explain the difference between BF% and BMI, understand and do the calculation you suggest and/or find a repeatable, reasonably accurate was to measure bodyfat %.
BMI on the other hand is 2 numbers most people know or can easily get on a repeatable basis plugged into an on line calculator that will provide a directionally correct number for the vast majority of the population.
4 -
MarkusDarwath wrote: »rankinsect wrote: »Unless they're paying for a DEXA scan, though, or maybe a BodPod, the reality is that most methods of measuring body fat % have such a large margin of error that they are probably even less reliable than BMI as a tool to calculate goals from.
I agree there is a fairly large margin for error. I disagree that it's less reliable than BMI.
There are basically two approaches for home measurement:
1. Bioelectrical impedance - can vary by as much as 5% just over the course of the day due to hydration changes. It can be accurate at the population level but almost useless at the single individual level.
2. Measurements based on anthropometric averages - all forms of calipers, measuring tape, etc. This suffers exactly the same problem as BMI (not surprising since BMI *is* an anthropometric approach, one that uses height and weight measurements) - individuals don't carry their body fat in a "perfectly average" way. If the distribution of fat on your body is significantly different from the population average, these can be grossly wrong.4 -
I think we should all just throw darts at a board to decide.8
-
3dogsrunning wrote: »I think we should all just throw darts at a board to decide.
It's not that hard, really. There is no one "ideal" weight for an individual. If you are generally within your BMI normal range or slightly outside the bounds, if your waist is not relatively large, if you like what you see in the mirror, if your health parameters are fine, then you are likely fine.
BMI is not meant as a diagnostic tool, neither are other things like body fat. Some people may benefit from additional weight like those with bone density issues, other people may benefit from being skinnier than average like those with T2 diabetes. Some people are generally in good health and their "ideal" weight is solely based on aesthetics. For some people being overly muscular is good for their purposes like for body builders, for others being overly muscular is detrimental to their performance like for endurance athletes. It's a sliding scale for individuals, really, people just like to argue the minutia.3 -
Simple test for the guys Take a cold shower. While in the shower, look down, if you can see your junk without bending over or using a mirror, you're probably okay.8
-
I used my favourite leather belt and wrote my waist measurements beside each notch (on the inside!). 34", 35", 36" etc. That way I could know at any point in time what my waist measurement is. As a rule of thumb you might aim for your waist to be about half your height. For a 6 ft person that means a 36" waist. For a 5' 10" person like me that means a 35" waist. This is the cheapest and most effective way of measuring your progress. In the absence of a more accurate DEXA scan, waist measurements are a marker for the visceral fat - the abdominal fat around your internal organs that are correlated to many health risks. Having a waist of 1/2 your height means you're looking good. BTW for the ladies, a waist to hips ration of 0.7 is considered attractive by many men and suggests fertility.
Not sure where you got this bogus info but I couldn't give a flip what ratio is considered attractive to men (what men are we talking about?) or if it (incorrectly) indicates my ability to bear their children. Thought we were talking about health here?
I've run out of things to say in this thread as rebuttals- I stand by everything I said so far- thanks to those continuing to fight the good fight. Some outrageous claims have been made that I just don't even know how to begin addressing (the government being taken over by vegans or something... can't help you with that).
My broken record statement: BMI is just fine for most people. People in overweight nations tend to underestimate the amount of extra fat they carry. Yeah.
12 -
I used my favourite leather belt and wrote my waist measurements beside each notch (on the inside!). 34", 35", 36" etc. That way I could know at any point in time what my waist measurement is. As a rule of thumb you might aim for your waist to be about half your height. For a 6 ft person that means a 36" waist. For a 5' 10" person like me that means a 35" waist. This is the cheapest and most effective way of measuring your progress. In the absence of a more accurate DEXA scan, waist measurements are a marker for the visceral fat - the abdominal fat around your internal organs that are correlated to many health risks. Having a waist of 1/2 your height means you're looking good. BTW for the ladies, a waist to hips ration of 0.7 is considered attractive by many men and suggests fertility.
I'm not convinced by this, for a couple of reasons:- it's far too easy to wear a belt at the same size and have a belly cascading over the top of it - when I started I was 220lb / 41" waist wearing 38" trousers and belt at probably 39" (and BMI 31.5 to bring the other half of the thread into the discussion).
- By my own anecdotal experience, 35" waist is still carrying a lot of excess abdominal fat - I'm now down to 30.5" (164lbs / BMI 23.5) and still carrying enough abdominal fat that I reckon I need to shift another 4 or 5 pounds
1 -
MarkusDarwath wrote: »According to his stats, Bolt is 6'5", 207 lbs.
Right, he's a good normal size for his height, other than having much less fat than most.He is not even close to lean-looking IMHO. He is a solid chunk of impressive muscle.
Lean means "not fat". You can be lean at a low muscle mass or at a very high muscle mass.
The standard presented by the BMI charts promotes an "ideal" of normal to low body fat combined with low muscle mass. There is no health benefit to having less muscle. The average person would be healthier at a low-normal body fat with an amount of muscle that would push them to the top end of "healthy" or into "overweight" according to BMI. BMI is absolutely not an optimal health standard.
I don't think you know how much of a difference in look even a small amount of extra muscle makes.5 -
MarkusDarwath wrote: »And I have always been told that bio-electrical impedance is at best only good to evaluate whether your BF% is trending up or down, not to get an accurate number.
This is true, and yet it's still more accurate than BMI.
Or if you don't trust BIA there are a myriad of other formulas more accurate than BMI where you can take some measurements and type them into a web site. Height to waist ratio, and the formulas the military branches use when BMI fails and they "go to the tape" both come to mind.
A metric that can change by multiple percentage points within 10 minutes? Yeah right.5 -
A lot of people slate BMI and cite some extreme fitness or sports person as the reason why BMI is wrong. It may be a surprise to learn that most people are not professional American football players nor competitive bodybuilders. For the average couch potato a high BMI might be enough to frighten someone into standing up.9
-
bennettinfinity wrote: »Gallowmere1984 wrote: »just my 2 cents worth here, I believe that while BMI can be a useful tool in determining a healthy weight, it is not the only tool that can be used. Personally, I track a variety of things to tell me how I'm doing, including my BMI, my waist to hip ratio, my waist to height ratio, and a rough estimate of my BF% (figured out from an average of 3 different online calculators and a set of calipers that I own) to figure out my healthy weight range. BMI in my opinion is a good starting point for those who aren't as familiar with different ways of measuring their progress.
Yes, anyone who is serious about changing their body has very likely used many more measurements than just BMI. As has been stated here many times, it's a fantastic starting indicator, but should be used alongside things such as bodyfat, tape measurements, etc. That being said, statisticians (what BMI is really good for) don't exactly have the time to roll around popping tapes, pinching skinfolds, and asking for DEXA results on every third member of the population.
As for the rest of the thread's argument: if the world had as many heavily muscled individuals with sub 12% bodyfat as it does landwhales who are pushing 35%, I would agree that BMI is useless. Take a good hard look around though, tell me that BMI is useless for the population at large, and I'll conclude that you're either blind, or have fallen into the cognitive dissonance trap.
I think this is exactly the point of contention - BMI is a great metric for studying populations - in fact, that's exactly why it was created - but it's not so great when applied to individuals; for a multitude of reasons.
Per your example above, you could have two individuals of identical height and weight; one at 12% BF another at 35%... both would be classified as 'Obese'... the inability to distinguish between two radically different individuals is the hallmark of a weak metric.
So, how many people do you think actually have that problem?
At 5'10'' I'd have to be over 210 pounds with 186 pounds lean mass. Looking again at the chart with max potential lean masses, that's 25 pounds over what is expected to be possible without "helping".5 -
Ooh, I've just been completely won over to the 'estimate BF% using a tape measure' method, because the Internet thinks I'm 18.5% fat, which sounds much thinner than 21.5 BMI. I'll just go with that from now on.
5 -
Ooh, I've just been completely won over to the 'estimate BF% using a tape measure' method, because the Internet thinks I'm 18.5% fat, which sounds much thinner than 21.5 BMI. I'll just go with that from now on.
Heh, even the USMC bodyfat calc, which uses five measurement points instead of the typical two to three, told me that I was 11.9% bodyfat, when I was still more like 16%.
*kitten*, a seven point, triple averaged caliper test now tells me 9.6%, and though I may have visible striations in shoulders and neck, visible veins near the lower abs, etc., I still don't buy it. I need to stop being a cheap *kitten* and get a DXA done.0 -
Yeah, I think the idea behind the waist to height ratio is that the waist shouldn't be more than half the height, not that it's necessarily an ideal waist measurement.I used my favourite leather belt and wrote my waist measurements beside each notch (on the inside!). 34", 35", 36" etc. That way I could know at any point in time what my waist measurement is. As a rule of thumb you might aim for your waist to be about half your height. For a 6 ft person that means a 36" waist. For a 5' 10" person like me that means a 35" waist. This is the cheapest and most effective way of measuring your progress. In the absence of a more accurate DEXA scan, waist measurements are a marker for the visceral fat - the abdominal fat around your internal organs that are correlated to many health risks. Having a waist of 1/2 your height means you're looking good. BTW for the ladies, a waist to hips ration of 0.7 is considered attractive by many men and suggests fertility.
I'm not convinced by this, for a couple of reasons:- it's far too easy to wear a belt at the same size and have a belly cascading over the top of it - when I started I was 220lb / 41" waist wearing 38" trousers and belt at probably 39" (and BMI 31.5 to bring the other half of the thread into the discussion).
- By my own anecdotal experience, 35" waist is still carrying a lot of excess abdominal fat - I'm now down to 30.5" (164lbs / BMI 23.5) and still carrying enough abdominal fat that I reckon I need to shift another 4 or 5 pounds
0 -
Agreed. I'm the same weight I was 5-6 years ago, but I've lost a few pounds of fat and gained noticeable upper body muscle mass since then.stevencloser wrote: »MarkusDarwath wrote: »According to his stats, Bolt is 6'5", 207 lbs.
Right, he's a good normal size for his height, other than having much less fat than most.He is not even close to lean-looking IMHO. He is a solid chunk of impressive muscle.
Lean means "not fat". You can be lean at a low muscle mass or at a very high muscle mass.
The standard presented by the BMI charts promotes an "ideal" of normal to low body fat combined with low muscle mass. There is no health benefit to having less muscle. The average person would be healthier at a low-normal body fat with an amount of muscle that would push them to the top end of "healthy" or into "overweight" according to BMI. BMI is absolutely not an optimal health standard.
I don't think you know how much of a difference in look even a small amount of extra muscle makes.
0 -
Some outrageous claims have been made that I just don't even know how to begin addressing (the government being taken over by vegans or something... can't help you with that).
It's just as well, because the way you phrased that is an absolute straw man and not at all what I said anyway.
0 -
darrensurrey wrote: »A lot of people slate BMI and cite some extreme fitness or sports person as the reason why BMI is wrong. It may be a surprise to learn that most people are not professional American football players nor competitive bodybuilders. For the average couch potato a high BMI might be enough to frighten someone into standing up.
The thread is about determining one's ideal weight. The "ideal" part pretty much excludes couch potatoes.
I'm not saying BMI isn't 'close enough' to BFP for the beginner. I'm saying that as one approaches ideal fitness it tends to be too far off for two many people, therefore is not a good measure for determining goals.0
Categories
- All Categories
- 1.4M Health, Wellness and Goals
- 391.2K Introduce Yourself
- 43.4K Getting Started
- 259.7K Health and Weight Loss
- 175.6K Food and Nutrition
- 47.3K Recipes
- 232.3K Fitness and Exercise
- 387 Sleep, Mindfulness and Overall Wellness
- 6.4K Goal: Maintaining Weight
- 8.5K Goal: Gaining Weight and Body Building
- 152.7K Motivation and Support
- 7.8K Challenges
- 1.3K Debate Club
- 96.4K Chit-Chat
- 2.5K Fun and Games
- 3.2K MyFitnessPal Information
- 22 News and Announcements
- 896 Feature Suggestions and Ideas
- 2.2K MyFitnessPal Tech Support Questions