Some foods just seems to make you feel very full, even when it seems like you haven’t eaten a lot of them. Part of the reason is that some foods actually expand in your stomach after you’ve eaten them.
What about bananas? Do bananas expand in your stomach?
To a small degree, yes they do!
Foods with a lot of starches, wheat, or oats tend to expand when exposed to your stomach acid, just as they do when soaked in water.
Since bananas have lots of starch, they will expand a little after eaten. This is one of the reasons that bananas are a very filling food.