Sokka was always like "I'm starving!" And "Where's the MEAT??" and "Yay! Free food! Grab as much as you can, guys!" But...
They never starved, you know? Sokka went hunting or fishing whenever they stopped long enough-- and even if the catch wasn't as much as he wanted to, I don't recall them ever going hungry.
When they were low on money and supplies, Sokka got a job on a fishing boat (Storm Episode). Or asked for food and money, as thanks for saving the village (Hei Bei Forest/spirit-kidnapping episode). Or something similar, the make sure that even if supplies were low, the pot was never entirely empty.
That's a skill.
Contrast that with Zuko and Iroh. Their first attempt at fishing caught barely a mouthful. They went hungry often-- even AFTER they began to resort to begging and stealing. They couldn't forage because they didn't know how to tell the edible from the poisonous.
It's easy to view Sokka as just the funny guy: he cultivated that part of his image, even. It's EASY to say that elite fighters with Royal tutors and private schools, etc, are better educated or more skilled than some teen from the Southern Water Tribe.
But when push came to shove? When it came to personally ensuring that nobody goes hungry while they're on this epic cross-country quest?
Sokka had them beat.
And I think if Sokka ever couldn’t find or catch enough food for all of them, he would come back with what he had and say he already ate some of it.
“Ugh, you always think just because you’re the oldest you get to eat first,” Katara chides him. She rolls her eyes and grumbles under her breath about how boys are annoying and she wishes she had a sister.
Sokka just stretches casually and pats his stomach, hoping the rumbling will stay quiet enough that his sister can’t hear it.
Sokka’s constant insecurity with food and tendency to eat as much as he can at feasts etc. even though he’s perfectly capable of providing for the group indicates a past of food insecurity.
Remember in episode one, how desperate and invested he seemed out hunting with Katara? How uncertain it seemed that he’d catch anything, even though it’s made clear by the rest of the show he’s a competent provider? How angry he was when he blamed Katara’s “weird magic” for costing him the kill (he didn’t see the fish she’d caught with her bending)? The water tribe seem alright for food now (Katara’s just carrying around a fish to feed penguins later), but it’s likely that they were left hungry for awhile, during or after the Fire Nation attacks.
