still hungry?

Some snacks keep you full and some don't, and it's not really about calories. Here's which ones do:

Plain Greek yogurt with your own toppings. The best one here. You get 17 to 20 grams of protein, and buying plain instead of flavored means you decide how much sugar goes in instead of getting 15 grams decided for you. Fruit and a spoon of honey takes ten seconds.

Peanut butter toast. Around 10 grams of protein plus fat and fiber. It's calorie dense enough that it eats more like a small meal than a snack, which is either the point or not, depending on when you're eating it.

String cheese and fruit. Nothing impressive on its own, 6 or 7 grams of protein per stick, but the combination works and it takes zero effort.

These aren't bad for you, but they just won't keep you as full:

Popcorn. Three cups is about 90 calories with 4 grams of fiber, so you get a lot of food for very little. But there's almost no protein in it, so it fills you up without keeping you there. Fine when you want to eat a big bowl of something. Not what you want if dinner is still a few hours away.

Hummus with carrots. I've seen this sold as a protein snack and it isn't. Two tablespoons of hummus is about 2 grams of protein. It's a good snack because the carrots are nearly free and it tastes like something, not because the chickpeas are doing much at that portion.

Chips and guac. Better than chips and salsa, since the avocado adds fat and fiber. Still mostly a chip snack. Which is fine, that's usually what you wanted.

If you're eating between classes and need to get to dinner, pick from the first group. If you just want something, the second group is fine and doesn't need a justification.

A snack that doesn't hold you just turns into two snacks. Not because you lack discipline, but because you're still hungry.