How's the food on French trains?

When in France we want to talk about a bad sandwich we say it's a "SNCF sandwich"

I'll leave it to you to draw conclusions...

Do you have any recommendations specifically for Gare de Lyon?

Yes, Le Train Bleu.
https://www.le-train-bleu.com/

I've been happy with food I've picked up in train stations all over Europe. In France, I'm especially happy if there is a Paul.

I was just about to post that there is a Paul boulangerie in Gare de Lyon! Pick up a great coffee, sandwich and a wonderful dessert. The lines can be long because their products are very good. I can't comment on train food, though. Get on the train and enjoy!

If you watch the vlogs of Thibault at Simply Railway, he likes the food on trains. But every train station is full of restaurants and stores with takeaway food, so it's probably simpler and cheaper to DIY before you get on board.

You should also watch his takes on any trains you may be taking for tips and looks.

I recall touring Lyon for a few hours as a stopover. On the way to Part-Dieu to catch our train to Geneva, we were hungry and we thought we would try the Micky D's next to the station. The lines were huge, so with time running out, we went in the station, and no line, got a couple of ham and cheese baguettes. We devoured them on the train and they were dee-lish.

The food on board the TGV is not bad these days (for example I had an excellent lentil salad earlier today on my way back from Mulhouse), but the price-quantity ratio is bad and it would cost quite a bit of money to be appropriately fed for the whole 6-hour journey. Also, the bar is not always well-stocked and some menu items are often missing.

There are many options at Gare de Lyon. I like Prêt a Manger and Depot Legal sandwiches, personally.

Thanks all! We'll plan to pick up something from the station to eat on the train in that case. I had thought to get wine from the bar to go with lunch, so thanks for the note about it not always being well stocked so I can plan that ahead too. I'm still chuckling at "SNCF sandwich" haha.

We once ate in the dining car -- there aren't many of those anymore. The meal was expensive and lousy. Now on longer trips we take picnic foods -- fruit, carrots, cheeses, good bread and water -- you could take a bottle of wine. Sometimes bakeries have small bread loafs that seem to be baguette type dough but that have olives, and or cheese and ham kneeded into them so that you don't need a sandwich -- the savory goodies are in the bread. We like those for travel or for snacking since we find that sandwiches don't keep all that well. I sometimes make my own jambon beurre because bakeries never use enough butter or ham. There is a type of cookie you find in supermarkets called Gerbles (we just call them gerbils) that are the sort of thing you can eat for breakfast -- and come in many flavors. We like sesame. They also come in little foil packets of 5 in their boxes, so they are good travel food. We tuck a packet in our jacket packet if out and about

You can buy coffee or crisps or soft drinks in the bar car to augment -- but I'd just bring travel stable foods that you enjoy -- for us it is usually bread and cheese.

I’ve gotten sandwiches, cookies, pastries, etc. from the Pret-a-Manger there several times before a long train ride and have been very happy with taste and freshness for what it is.

Olga is a wonderful little shop across the street from Gare de Lyon. They have a few different sandwiches every day. Much better quality than Paul, and a good value lunch combo.

I don't remember the name of the shop but we stopped at a little shop, maybe the one you recommend, across from Gare de Lyon last fall on our way to Montpellier for our train food and got quite excellent sandwiches as well as fruit and pastries. We had only spent one night in Paris and so didn't at that point have a kitchen to make our own.