I have found my youngest darling daughter will point to the treats cupboard when she starts to get peckish before dinner, and started to even at a young age.
That is why a tip that I now use is, don't always use the same cupboard. If you move the treats around when you unpack your shopping they dont get used to them being in the same place. You can tell them there aren't any goodies in there and only bring them out when you want to.