Eat, every time you remember to, even if you aren't hungry. Even if you're nauseous (oddly, eating can fix that nausea a lot of the time). If you have to, drink it. Like Ensure & weightlifter protein smoothies, not Coke/Pepsi, but soda is still better than water when you're not eating. (Brain runs on glucose. If you're not feeding it sugar every day -all sugars break down into glucose for your brain) then it starts breaking down fat/muscle/organs trying to get the glucose it needs (and the nutrients your body needs)... Also known as ketosis.
I was doing triage in the ER during the Atkins craze. Where people were cutting out all sugar. And every night we'd have at least one (sometimes more) coming in with ketoacidosis. Delusions, hallucinations, seizures, coma, death. Fun shit.
People make fun of my soda habit, but it's half so that when I do hit a rough patch (like now) and keep forgetting to eat? I'm not starving my brain. Poor old thing has enough wrong with it not to have to go through seizures on too of everything else!