Hello @confusingthings, Welcome to Connect. I've never tried this but it is an interesting question, just seems like a lot of work though. Psst, maybe that's because I'm a really old guy.

--- How to Measure Body Fat Without Calipers: https://www.livestrong.com/article/90931-measure-body-fat-percentages-calipers/.

I find a cheap bluetooth bathroom scale that shows body fat, muscle mass, water weight and BMI much easier to use and you only have to step on the scale barefoot in the morning. This is the one I have ($29) - https://shop.greatergoods.com/products/greatergoods-smart-scale-bluetooth-connected-body-weight-bathroom-scale-bmi-body-fat-muscle-mass-water-weight-fsa-hsa-approved-black-stainless. It works with their Weight Gurus app - https://weightgurus.com/.

There is some truth to the old saying you are what you eat. I know it probably doesn't mean anything and not very helpful but I can remember being 18 and working at the original McDonalds in San Bernardino, California growing up.
At that time we were allowed to eat whatever we wanted during our shift break and I think that's where I started my journey with some really bad eating habits which led to some of my current health issues.

Do you mind sharing what your main concern is? Is it gaining too much weight?