4 ms·
Weight is a poor metric to track in isolation, prone to error. Much more robust to also track waist circumference. There is actually a neat formula called the
by graeme 4y ago
Weight is a poor metric to track in isolation, prone to error. Much more robust to also track waist circumference.
There is actually a neat formula called the navy formula to estimate body fat and lean mass from four variables for men and five for women. For men: waist circumference, weight, neck circumference, height. Women should also add hip circumference.
There are calculators online, but for anyone interested I expressed the formula into this Shortcut for Apple devices. You enter your height (do this once, in the blank text field above height)
Then, measure your neck circumference and remember it. This won’t change much. I measure mine maybe once every 1-2 months or if my other measures changed significantly.
Then, whenever you would normally weigh yourself, measure your waist too. Then enter weight + waist + neck circumference. The Shortcut will then calculate the following and log to Apple Health:
* Weight
* Waist circumference
* BMI
* Estimated lean mass
* Estimated body fat
The last two obviously have an error, but it will be a fairly consistent error so the trend over time will be clear.
For instance recently I gained a bit of weight. But my waist circumference went down a little. So my weight increase is actually muscle, and I’m going in the right direction.
Shortcut is here: https://www.icloud.com/shortcuts/1be74cce1ac24c03821feb7e36d47e45 https://www.icloud.com/shortcuts/1be74cce1ac24c03821feb7e36d...
Don’t have a woman’s version unfortunately, made this for my own use. If there’s interest I could probably create a version that includes hip circumference
- AnonHP 4y agoDoes this assume specific units for the measurements of weight and circumference? If yes, what are those and how would one change the formulas for other units of measurement?
- graeme 4y agoOh right, this one is inches and pounds. You would change it by going into the shortcut and entering different conversion figures based on the formula in metric instead
- anothernewdude 4y agoNavy Formula calls me an athlete and is SORELY mistaken. BMI accurately calls me overweight, but is probably mistaken about how much.
- graeme 4y agoIt’s more about direction than absolute level. It has my body fat far too low I think but I can see it change with my waist/weight over time
- pc86 4y agoBMI being accurate is really a broken clock being right twice a day sort of thing. If you have any appreciable muscle mass, or do any sort of training beyond just running (or run a lot) BMI is wrong almost all the time.
- graeme 4y agoI prefer waist circumference, but BMI is not far off for most people. I’m quite muscular, only times I ever hit “slightly overweight” on BMI I also had a small gut I checked the the BMI of elite hockey players ranged from 25.5 to 27. And that’s for rather muscular people, also tall, at the far edge of the “high bmi, not overweight” spectrum. Virtually guaranteed if you have a BMI 28-29+ as a male you also have excess waist circumference. The idea that BMI is comically wrong is…well, wrong.