Waaaay easier than expected.
I'm very used to intermittent fasting, eating only 1-2x a day, so the first 24 hours are not hard for me. 36 hours I hit some pretty good rumbles, but some good salt (a big pinch) in a glass of water knocks that out.
48 hours things got weird. I was not physically hungry, but I was dealing with mental habits of eating.
72 hours I noticed a sweet taste in my mouth very likely a sign a pretty deep ketosis.
Coming up to 96 hours my smell sharpened considerably. I could smell things 2x the distance away than normal. It's nutty.
Keys to make it as easy as possible:
Light movement. Walking helps a ton. Stretching is also good, but you need to do it for an extended period of time. 45 minutes minimum at least once a day. This greatly helps prevent much muscle wasting and actually helps quash hunger pangs.
I don't know how doing a more strenuous workout would feel.
Salt your water when you feel physical hunger.
Keep busy to distract your mind from obsessing over food. Or, alternatively, simply observe how your body and mind react to not eating. Eating /cookingtakeup time and energy that you now have for other things. Your focus and sharpness of attention are heightened. Use this to think (or pray if you are so inclined).