The secret to ensuring satiety with soup is to ensure you sneak some extra protein in. This could be a broth with poached chicken &/or edamame beans, make a minestrone but use red lentil pasta, quinoa or beans/chickpeas, blend collagen powder, cottage cheese or yoghurt into a veggie blend, or perchance you fancy a tortilla/chilli-esque soup with mince of some kind. The possibilities are plentiful and in this recipe I've used silken tofu as my hidden protein. It’s totally innocuous in flavour so whether you love or hate tofu it doesn’t really matter, it just disappears into the blend & you’re left with a winner of a lunch/dinner.
Don’t forget the texture too - chewing triggers the satiety response so just drinking a smooth soup won't fill you up; make sure there's something to chew.