For me, its when I am satisfied. Not immediately after a meal, but not when I'm hungry, either.It doesn't make much of a difference, though. What is really important is that you are focused and centered, and not distracted by 'I'm so hungry!' Or 'That was sure delicious...' Because those thoughts of yours can severely interfere with the thoughts of the person you are trying to read. I find that at night, my ability is enhanced quite noticeably. I am not sure as to why, yet, though... :) Hope this helps.
There have been many theories about this over the years. Some people say it is easier to connect to the spirit world when you are hungry this comes from the belief that spirits are in a constant state of hunger, hunger to talk to loved ones in the physical realm and a hunger to complete unfinished business. Some theories say it is easier to connect when you have eaten because then your mind isn't preoccupied with thinking about being hungry. I personally pick up on the same things whether im hungry or have just eaten, I think it honestly depends on how long you have practiced and how strong your connection to the spirit world is.
I would say neither for connecting to other physical entities, or which ever you think less about. You want a clear head, peace of mind. Normally you want to be well fed but not full.
Think about focus, you need focus to do accurate readings and when your mind is on food your results might be compromised.
What you listed are intuitive abilities that are either stand alone and information is gathered from information sources you have links to or you can channel information from spirits. Different methods for both will tell you different things. What's mentioned above being easier to connect to spirit on an empty stomach is one example, however that's normally for a more spiritual approach than just practicing simple ExtraSensory Perception (ESP). Behind that would be the idea by being hungry you're detaching yourself from worldly matters becoming a more appropriate vessel for the knowledge you're attaining. Again, these abilities don't require spirits to tell you what you're wanting to know you can develop stand alone ESP where you gather information from what's physically around you. Depending on the ability you're wanting to tap into you might find one or the other (spirit or physical source) more appropriate which might help you decide whether you want to eat first or not.
My advise is decide for yourself.
Hope this explains things and kind of bridges the gap between theories for you.
Just a sidenote*: I have found that drinking a glass of water and then opening and clearing your Chakras before giving readings is the best approach that I have found works wonders for my abilities! :D
