Snacking on the go?

I've lived in a few cities now, and I feel so out of place when I have a bar/banana/snack while walking to my destination. I grew up near NYC, and l'm a dancer, so I'm used to eating when I can, but I find it so strange that no one in San Diego eats on the sidewalks. They all have drinks, water or coffee, but no snacks. I know eating in the car is a thing, but I do more walking in the city. Is eating while walking common where you are?