I think you can kind of approach it like "Would I eat these ingredients on their own if they weren't smashed up together?"

The first recipe I find is 1 banana, 2 cups of strawberries and 1/2 cup of yogurt and a 1/2 cup of milk, resulting in two servings.

I would definitely eat that unsmashed so I imagine the smoothie version is fine, and it's only 200 calories. Still definitely a dessert type snack though.