I know just how you feel!
when i go shopping I let everyone pick out their own snack. It's funny because they all still have a full supply, and my nuts are almost gone, and not from me either! I am going to start buying less of their junk and more of mine, i bet then they complain they don't have the other stuff!!!
I would try hiding your personal snacks in your room, or keep things in your car.
one trick that works well is putting it in a bag and placing it in the back of the fridge. MOST men will not take the time to open it up and look inside.