How should I deal with my wife's repeated (up to 4 or 5 times) trips to the bathroom before meals?

I tell mom 30 min before her meal that its time to eat..she goes to the bathroom and then eats.

It's common for someone with dementia to have patterns around the bathroom. Fortunately, it's just around meals and not all day and night long (which is my current experience with my mom). I think you have gotten very good advice to let it be and work around her patten and not focus on it too much. It's difficult to witness, I understand. And hopefully this pattern just stays around meals and eventually stops. It might also help to talk to her doctor about it as he may be able to help in some way.

Rick80: She may need to see a urologist.

Have you had her to the urologist? A scan of the bladder after voiding will show whether or not she is completely emptying her bladder when she goes. There are meds to help with this if that is the case. This takes little time and is easy for the procedure to be done.
Also the leaning over JoAnn mentioned can help put pressure on the bladder to empty.

My mom had a procedure for this that helped. She also took a partial pill she thought helped.

“Someway to convince” is a nonstarter. And also, sitting on the toilet for a long time is not a good practice.

https://my.clevelandclinic.org/health/diagnostics/16423-postvoid-residual

This link gives more info. My mom just had the simplest version right in the doctors office. Very routine for urologist.

Another good link.

https://www.alzheimers.org.uk/get-support/daily-living/toilet-problems-continence

Plan ahead for those trips by making a 6pm dinner start at 6:30 from now on. Ask her to come to dinner at 6, and that will give her 30 min to go back and forth to the bathroom. Cuz ya not changing the AD behaviors, that's for certain!

Good luck to you.

Does this simply happen before breakfast?
If so, don't pay it a lot of mind as it will cement the obsessive behavior even more in her mind. This may have to do not with urination, but with a need for a bowel movement.
If this doesn't continue down throughout the day I would simply accept this as her routine. Your own need to keep breakfast organized as you would like it may be a clash with some habit she has formed for some unknown reason.

I would just let this one go, and hope it doesn't progress.

Hard when she has Dementia. Tell her to sit till the feeling goes away. It was suggested on this forum to lean forward to help empty the bladder. It does help. I hope you have your wife in Depends. Incontinence can happen overnight.