When I eat snacks on my desk, I sometimes end up sharing my snack with my colleagues. I know it's good to share sometimes but every time they see a snack on my desk, they'll beg me to share it with them. It's very frustrating that because of this I cannot have my snack. In my company there is no policy about bringing foods to our desk. When I tell them to buy their own snack they seem to get upset about it.
How can I handle this situation? What can I do to make them avoid begging me for snacks?
(Updated Note: I'm a very busy person which is why I usually don't take breaks at the pantry. I usually eat my snacks at my desk.)