we would say that to convince kids to try it out, we let them play in the kitchen (in a safe environment), we let them cook with us and let them try the food straight away from the oven tray for example. you use it like a vest and also it generally has a stiff back that requires your back in the appropriate setting and holds your head up directly. i worked out about 20 tea spoons a day on average (shocking really, having thought i had a generally healthy diet). good luck, hope your boy snaps out of it soon. 