Our 5 year old is built super narrow. Even adjustable jeans would fall down when he runs. He LOVES this belt. It keeps his jeans on through all the playing, running, climbing and yet is still easy enough for him to get them up and down. He has plenty of room to grow as well.
This belt is high quality and very hip .. My 6 year old wears it to school with his uniform . It works perfectly because it snaps easily . I highly recommend it