In college I developed a pretty bad habit of eating one meal a day: I would sleep in past lunchtime and just have a large dinner. But it feels worse now, like the brain fog or excessive daytime sleepiness--not sure if it's because I'm home alone, or because I'm expending more energy exercising, or maybe I'm just misremembering and it was equally bad in undergrad.
I've started taking some vitamin D supplements (because I never see the sun during the week), eating healthier snacks (e.g. Greek yogurt, crackers and hummus as opposed to Welch's fruit snacks) in addition to eating lunch (and occasionally even breakfast), and I think it's helped? Kind of hard to measure. In general, I also cut down on calorie intake quite a lot compared to home, where we store a lot of junk food, and college, where I would eat out almost every meal. I don't track the numbers exactly, but have just generally reduced portion sizes, although perhaps the snacking indicates I took it too far.
Also not sure how real chronotypes are--not sure if I'm actually a night person or if I just need to fix my sleep schedule. It's just so easy to stay up, and I feel a lot more productive in the wee hours of the night. Ideally I would just stay awake until I feel tired, and then sleep until I naturally wake up, but I typically don't feel tired until real late at night.