I stand behind this guy being a mumrik, which explains his natural inclination towards fish in the series. But it also explains a lot of his eating habits in general, he’s rarely seen eating with other people unless it’s a big event or Moominmama has made a big meal. So it’s no stretch to say that like most other things, he prefers to take his meals alone.
Plus, he’s a very polite person, so it would be very far-fetched to imagine he’d everinvite himself to a meal, even if he knows it’s something open to everyone, like most meals held in Moominhouse. This politeness can backfire on him sometimes, of course, because even if he truly is starving, he likely won’t take a place at a table unless he’s directly invited. (something Moomin catches onto after overhearing his tummy a bit too many times around dinnertime)
I don’t imagine his tummy itself being particularly loud, when mealtime rolls around one could expect his stomach to sound off with quiet little grumbles. Of course, his stomach will complain louder the longer he goes without proper food, but considering he’s usually pretty well-fed in Moominvalley, one could only expect to hear his stomach reallygrowling if he’s had bad luck fishing and foraging.
Snufkin’s stomach is actually at its loudest when it’s stuffed; he’s not used to big filling meals multiple times a day or feasts in the same way the Moomins are, so when he does get the chance to indulge, his stomach has to work rather hard. It’s not uncommon for Snufkin to retreat back to his tent after a large meal, partly to be alone after a social function, and partly to avoid any comments he might get about his gurgling tummy.
He is also absolutely not immune to overindulging on Momminmama’s cooking; not only can the Moomins eat far larger portions than him, and he tries to match those portions and clear his plate to be polite, most of the time the food is just that good and he truly can’t help but to eat a little more than he can manage.
(TW: Brief mention of weight gain/loss) I am personally a soft Snufkin enjoyer, I see a lot of lovely fanart where he’s drawn as your Regular Skinny White Boy™️ and while that’s a great take, I can’t help but think he has a little bit of a tummy, almost in the same way cats have a little pooch. Especiallywhile he’s staying in Moominvalley, there’s just too much good food for him not to put on a healthy amount of weight. He probably sheds a bit of that weight during his winter travels when filling meals are harder to come by, but his time in Moominvalley more than makes up for any meals he might have missed during the winter.
To dip a little into angst, Snufkin probably does hoard food when he notices it starting to become scarce. Considering he’s a mostly self-sufficient person who has been traveling since he was very young, I wouldn’t be surprised if he experienced one incident where he really couldn’t get any food that caused him to begin saving things for rainy days. He has safety nets and is better equipped to take care of himself now, but it’s a habit he can’t seem to shake.
