coffee definitely ruins my sleep no matter what time I drink it, so there's that.

My father also had headache his whole working life on Sundays, not realizing that drinking coffee all week days but not on the weekend, that was probably coffee withdrawal that was giving him a headache by day 2.

Even coffee is without its downsides and risks. There are cardiovascular risks, acid reflux, sleep issues, and probably more.

I though GERD was not caused by coffee [1]: "Drinking coffee or tea and adding milk or sugar was not associated with reflux symptoms or EE"

[1]: https://journals.lww.com/tcmj/_layouts/15/oaks.journals/down...

Certainly is a problem for me and I've seen others say the same. Every doctor I've been to has mentioned it as an issue.

"Caffeine — a major component of many varieties of coffee and tea — has been identified as a possible trigger for heartburn in some people. Caffeine may trigger GERD symptoms because it can relax the lower esophageal sphincter (LES)."

https://www.healthline.com/health/gerd/coffee-tea

I get really bad GERD from coffee and black tea, a bit less from green tea.

I don't get GERD from Mate tea or energy drinks. So I think it's not the caffeine. Since they both contain high amounts of caffeine, even higher than black tea.

I've noticed that if I eat more fiber I can somewhat mitigate this. But it needs to be consistent. Not just a little extra fiber before coffee.

BTW a high-fiber diet can be a natural ozempic by raising GLP-1 levels.