from Hacker News

Move over BMI .Welcome BRI

by dr_ on 9/6/24, 10:07 PM with 10 comments

  • by beingfit on 9/7/24, 5:08 AM

    > But those who were least round were also at elevated risk of death: People with B.R.I. scores under 3.41 also faced a mortality risk that was 25 percent higher than those in the midrange, the study found.

    > The paper’s authors suggested the lower scores, seen mostly in those 65 and older, might have reflected malnutrition, muscle atrophy or inactivity.

    > “B.M.I. cannot distinguish body fat from muscle mass,” Wenquan Niu, who works at the Center for Evidence-Based Medicine at the Capital Institute of Pediatrics in Beijing and was a senior author of the paper, wrote in an email. “For any given B.M.I., fat distribution and body composition can vary dramatically.”

    So, if I understand it right, BMI cannot distinguish body fat from muscle mass and BRI can’t distinguish malnutrition or inactivity. This would mean that whichever metric you choose, you should look at it as well as beyond it.

    On the same topic, the formula for BMI is a simple one (weight in kilograms divided by height in meters squared) that you could calculate it on a simple calculator.

    The formula for BRI is more complex: [1]

    > BRI was calculated as 364.2 − 365.5 × √(1 − [waist circumference in centimeters / 2π]² / [0.5 × height in centimeters]²), according to the formula developed by Thomas et al.

    [1]: https://jamanetwork.com/journals/jamanetworkopen/fullarticle...

  • by asdfasvea on 9/7/24, 5:16 AM

    Perfect is the enemy of great.

    Oh no BMI gives weird results for 2% of the population, who by the way are acutely attuned to their bodies, so let's throw the whole thing out.

    Health professionals need a polite way to start obesity conversations with patients and BMI gives them that. When you focus on the very narrow shortcomings of BMI you actually harm obese people by giving them a reason to disregard concrete measurements of their obesity.

  • by pedalpete on 9/6/24, 11:06 PM

  • by pedalpete on 9/6/24, 11:08 PM

    Why would we bring in this new metric which does not seem like a significant improvement, when we have other tools to measure our health regardless of physical representation?

  • by Krssst on 9/7/24, 4:27 AM

    https://jamanetwork.com/journals/jamanetworkopen/fullarticle... gives the actual formula in "BRI Definition " for the curious.

    (wonder if they needed to specify the unit in the first place since lengthes end up being divided together. Maybe to avoid people using different units for height and waist length?)

  • by afpx on 9/7/24, 6:48 AM

    They've always said my BMI was high even when I've had very little body fat. I just have naturally larger, denser muscles.

  • by RedAuburn on 9/7/24, 12:17 AM

    belt and road initiative? so true

  • by 486sx33 on 9/7/24, 12:14 AM

    BMI is important, and correct