OT: BRI is the new BMI...

[unterhausen]

I'd rather be fat than round. Unfortunately, I'm both right now. It makes it difficult to get in the drops and hammer.

[jimcav]

Originally Posted by JMT3

I’m less than 8 percent body fat.

On a 'population level' that 8% value really isn't healthy. Although good news is testosterone in inversely correlated to fat mass, but I digress: even highly aerobic athletes are rarely under 11%.

see table 5 showing whole body fat mass by sport % here:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4022746/

and essentially the same findings for NCAA Div 1 athletes (male ave. % body fat was 16%, none lower than 12.2%): :
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745817/

[nmrt]

Funny story about "asking people to look at me" to evaluate whether I looked fat-ish or not.

I am 5 ft 8 in and about 140 lb. In my opinion, I have a "decent" weight for my height. Not skinny like Kipchoge but not muscular like a rugby player.

I am sure in another country (not our US of A), I would be classified skinny. On the flip side, and I know this because I have experienced this, in a different country, I have been called "chubby". And I would not fault them because when I looked around in that country's population, I did look "chubby".

All I am saying is that people will judge your composition based on what they see around them.

Originally Posted by pdonk

As someone who is mathematically challenged, I had chat gpt run my number for BRI. Unless something went really wrong, I am nearly 2x the max "roundness" as someone my height should be. If you ask most people to look at me, they would say I look relatively fit and not over weight. I know I carry a bit of flab around my middle, but almost everyone in their 50's could use to change their body composition to be leaner or lose a pound or 2.

After an 18 month slog through my mystery illness with Drs, some of who put me on drugs to gain weight and being told by others I need to lose weight, I am skeptical of any value that is based on a mean body shape.

[marciero]

Both BMI and BRI are rather ad hoc. The latter was conceived by a mathematician but is still ad hoc in the sense that there was no science guiding the idea to use an ellipse as a model. And in fact the two coefficients in the formula were chosen out of convenience simply to get the values in a convenient range. I do think BRI is a clever idea however - something simple that predicts VAT fat. Bonus points for using a circle.

Two things going on here. The main paper from JAMA linked in the article is about the association between BRI and all cause mortality. As others have pointed out, this is about population level effects. There is nothing about patient level prediction. Unfortunately these types of results are often reported out in the media as "your level of risk increases..."

The second thing is that the BRI is, in fact, a predictor of VAT fat. That is established in one of the references of the JAMA paper. This is a patient- level prediction result; that is, at the individual level. Its the relationship between VAT fat and all cause mortality that is a population level effect.

I only perused the two papers but I do note that the paper establishing BRI as a predictor of VAT states found only "slightly improved" predictions of body fat and VAT compared to BMI.

[makoti]

Originally Posted by jimcav

and essentially the same findings for NCAA Div 1 athletes (male ave. % body fat was 16%, none lower than 12.2%): :
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745817/

I wonder what that would be if you simply excluded football linemen?

[benb]

Originally Posted by makoti

I wonder what that would be if you simply excluded football linemen?

I mean all football players should be excluded because even if they're not weird outlier guys like the lineman the rest of the team at the D1 level has a way way higher incidence of PED use than the normal population and PED use will increase BMI/lower body fat %.

I am curious what these BRI calculators are doing and how it estimates body fat.

My BRI is apparently normal but based on other kinds of testing the % body fat estimate the calculator comes up with for my measurements seems wildly high.

[jadmt]

I am a bowling ball by BRI standards and obese by BMI standards.....

[marciero]

Originally Posted by benb

I am curious what these BRI calculators are doing and how it estimates body fat.

The 2013 paper referenced in the main paper is the one that developed BRI and established it as a predictor of VAT and % body fat. They used various regression models with and without other other variables - age, height, sex, race, and weight. They included interactions and transformations of these variables also apparently. I'm seeing tables of R^2 values but not model coefficients but I'm sure they are easily found someplace

[dmitrik4]

Originally Posted by fourflys

one thing that hasn't been discussed so far is how BMI was used, I think back in the 60s, to create insurance actuary tables.. so basically, BMI was "weaponized" by the health insurance industry to determine rates based on this standard.. and I don't have any citations on this currently and, to be honest, I don't feel like looking them up.. so take it with a grain of salt I guess..

some of the military (at least Coast Guard and Air Force) have started using abdominal measurement for semi-annual weigh-ins.. (you can still meet max weight or BMI or fitness test as well for Coast Guard) the idea is if your gut is 39" or less, you are at an acceptable level.. they aren't saying you're healthy, but healthy enough I guess.. I can see some good data behind that if you looked at the health of most people that had a 40" or above waist.. heck, just look at the size charts for any cycling bibs.. the waist measurements would have you thinking any cyclist with a 38-40" waist will be over 6' tall.. not really realistic..

Exactly right. It’s a generalization that has been inappropriately applied to individuals. It’s only one high-level metric that doesn’t necessarily apply at all to any individual.

[bigbill]

Originally Posted by makoti

I wonder what that would be if you simply excluded football linemen?

That's a good point. The success stories are the former NFL or Div 1 linemen that drop weight after their playing days. My son graduated from the Naval Academy, where he lettered in cycling, and the senior football players have until graduation to be within body fat standards. Chicken breasts and spinach with lots of cardio. A friend of my son's who was two years ahead, injured his knee in week three of the season and needed surgery. He was a defensive lineman, about 6'3" and 280#, but put on another 20 pounds after surgery. He selected for Marines but couldn't meet standards on body fat or the run portion of the Marine physical fitness test, so he didn't graduate. He had all the hours for his BS (no BAs at USNA) but not granted his degree or officer commission. He ended up working out and enlisted in the Marines. After graduating from boot camp, he was given his diploma and became a second lieutenant.

When I was stationed in Hawaii, the Samoan and Tongan boys are encouraged to play football. It's not unusual for the offensive line to average over 300 pounds. If the kid doesn't get a scholarship to play football, they become a ticking time bomb of heart disease and/or diabetes because most will remain that size for the rest of their shortened lives.