Fukuoka day trip from Osaka

A well known Japanese chef in our country said that we absolutely must visit Fukuoka because of the food.
We already have hotel reservations for that time in Osaka, so we will have to do this in the same day and be back in Osaka in the evening.
We understand that it takes 2.5 by train on each way, do you think its worth it? what is special about the food in Fukuoka?, what else do you recommend to see there?, and are there any special onsens there?

Thank you!

This is really up to you, but I wouldn't recommend it. There are plenty of places in Kansai just as worthy (if not more so) of a day trip, where you won't lose 5 hours to travel and potentially a lot of money if you don't have a rail pass.

Is there anything you want to see/do in Fukuoka apart from eat?

I wouldnt. There isnt much to do and while the food there is good, I've been impressed with the food pretty much everywhere I've been in Japan. For nice towns close-ish to Osaka with good food, you could try Hikone (great castle and views) or Nara or Uji. If you want to have a bigger journey, Kinosaki Onsen would be a possibility.

The last shinkansen back to Osaka departs Fukuoka around 9pm. That gives you enough time to experience the food stalls of Fukuoka which I think can be a wonderful experience - despite being rather touristy. Here is an introduction about Fukuoka Food:
https://www.japan-guide.com/e/e4811.html

If you have the time and interest and if you have a rail pass that covers the Sanyo Shinkansen anyway, I would definitely consider making the side trip. If you don't have a rail pass, it would become a rather expensive side trip, though.

There are no noteworthy onsen in Fukuoka City.

..I did it as a day trip from Kyoto. I'd been to Kyoto/Kansai many times before, so missing a day for Fukuoka was not a big deal. Fukuoka was at peak or pretty darn close to peak for sakura and I was determined to be somewhere in Japan for peak that trip. So for me, it was totally worth it because sakura peak! I left Kyoto a few days later and it wasn't even close to peak, though oddly enough Tokyo was further along.

I guess if you were going when the ume in Dazaifu were peak and weren't going to Kairakuen, it could be worth it, but I know not everyone is as into flower viewing. I guess also going for their Gion Yamakasa Festival might be worth it as well? You don't say when you are going.

There are onsen in Fukuoka: http://www.fukuoka-onsen.com/english/index.htm

Have a look at you hotel reservation in Osaka. It might be possible to alter it for free so you can spend a night in Fukuoka and do also some sightseeing. Notably Dazaifu, or maybe Mijajima on the road.

If that is not possible, well the night stalls are an experience but only for food to Fukuoka without a specific place that you were recommended seems a bit lot of traveling for a bowl of ramen. Osaka is also known as a city with very good cuisine.

Enjoy your trip to Japan!

What was the chef saying what menu you have to eat and which restaurants reccomeded in Fukuoka?
https://goo.gl/EESAk2
Fukuoka gourmet is famous nation wide Japan, so you can eat most in Osaka.
Perhaps, guess the chef wants to advertise his hometown.

To/From Fukuoka you can take a night bus that is cheaper than Shinkansen,
but the domestic air(LCC, to FUK) is cheaper and faster than Shinkansen if stayed not so far fr KIX.

No worthless Fukuoka travel, but you can not eat all in a day, right?
Also worried that you can not be eaten by allergy and religion.

I suggest you check your hotel reservation in Osaka. There is a chance that it can be changed at no cost. In that case you could do a night in Fukuoka and do also some sightseeing, eg Dazaifu or Mijajima...

The night stands in Fukuoka are special, but doing all this as a day trip just to eat a bowl of ramen wouldn�ft pay off for me. If you have a very specific suggestion about a place where to go, then I would be slightly more in favor of the day trip idea. In that case her a reservation.

Also note that in Osaka food is also known to be very good. So if it is about eating well, you can achieve this in Osaka easily.

Enjoy your trip to Japan!

The food is awesome all over Japan. Unless you are going to Fukuoka for something specific, I wouldn't waste 5+ hours on transit.

I disagree with some of the above response that Fukuoka has not much to see. It is a city that will keep in entertained for a few days. So unless you can give it the time it deserves, I'd say skip it and enjoy 5+ extra hours in Osaka eating awesome food.