On any cycle pilgrimage food matters. Italy understands this well as pasta is perfect for topping up and restocking carbs. They also give you enough tomatoes and veggies to keep your vitamin levels high, your blood clean and happy, and your bottom on top form.
As a non meat eater Italy is perfect, they don't eat meat all the time, and do fabulous things with spinach. Spain does pretty well, with plenty of veg and fish choices, but France proved more difficult with menu du jour seemingly rotating between steak (horse) and veal. I've never eaten so many omellettes in my life, and that can have terrible digestive consequences.
Wherever I'm cycling I make sure to top up on fruit and carry some with me when I see it. It really makes a difference to how I feel.