How long does it take for ingested protein to show up in the urine?

[lmthoms00]

I have CKD3b. I’m trying to figure out what amount of protein in my diet will cause proteinuria/urine foam.

When I see foam, is it showing up because of protein I ate some hours ago or 24 hours ago or over the course of days?

How long does it take for ingested protein to show up in the urine?

Is the amount of urine foam mainly based on ingested protein or is it significantly affected by things I do that stress the kidneys such as eating potatoes, tomatoes,etc.?

Feel free to respond to any one or more of these questions. Feel free to discuss this even if you don’t have answers to the questions. Thanks!

[Michael__S]

It's different for everyone and your concern about how much protein you can eat and how often should be referred to your specialists. Those are the kind of concern that a RD can be of help. Everyone metabolize food at different rate, work with your medical team to find what works for you.

In short not everyone leaks the same amount of protein in their urine and your urine will change color as your kidney are filtering waste. And you will get foaming when the concentration is high enough .. or if you are dehydrated. But unlike protein it should only last a few minutes at most.

While I am fortunate to leak very little protein at the moment (except when I am sick), I realize that it's something to look for but not to overthink. Otherwise I would risk mild malnutrition by trying to avoid it too hard. Or worse, I had a few instances where I think it was caused by (mild) malnutrition itself .. it seems that bringing the missing nutrient in would create more metabolic activity which in itself would create more waste. Or something as simple as eating more soluble fibers, sign that I should increase my intake.

Or physical activity, to an extent. If it's after exerting myself too hard it's a warning sign but my urine will get darker if I had not exercised for a while. In which case I assume it's a good thing. In that regard monitoring CNS fatigue and inflammation are better indicator of what activity is sustainable than whether or not my urine is more frothy.

I hope this help.