I did it for awhile (re: various "Dave's losing the gut" threads over the last decade). And then I started introducing a rotating diet because it gets boring pretty quickly. But it WAS easy to follow. For me, the trick was distracting myself while eating, because it was boring doing plain chicken & broccoli every day, so I'd read ATOT or watch Youtube or something to distract myself from the boring meal. Then five minutes later you feel awesome because you just ate plain, whole foods with no preservatives or artificial anything. I went through a Soylent phase as well, which is probably the most convenient food on the planet, especially now that it comes pre-bottled & shelf-stable (worked great, FYI). Eventually I learned how to cook (especially with the Game Genies of food - the Instant Pot & Anova) and learned about IIFYM. So now I tend to eat great-tasting homemade food that fits my macros, with some junk food thrown in here & there (like Whoppers) for good measure.
I'm a big fan of the idea of eating a variety of foods, for a variety of reasons, including (1) so you don't go insane, because you're getting some variety in your diet, and (2) because we still know surprisingly little about the real effects of nutrition, how it affects longevity & disease, etc. We know what the minimum required to keep you alive (see the W.H.O.), we know what works for getting you in-shape through fat loss & muscle gain (macros), but there's still a lot we don't know. I do think eating real food is best for you body. But there's this weird dichotomy where even though whole foods make you feel awesome, that's not enough of an addicting draw to lure you in day after day - I'd still much rather live on fast food, take-out, and junk food all the time, but I also like to feel good & not be a butterball, so there's some balance involved.
My recommendation? If you use Gmail, send yourself an email every day with what you ate for the day. A personal thread of your basic daily food log. Optionally add in bowel movement times & results, energy levels, mood, etc., but at minimum, just write down what you ate for the day. It not only helps you track yourself when going through phases (I have ADHD, so my brain tells me that whatever I'm doing now is what I'll be doing forever & ever, when that's clearly not true, but that doesn't change how it feels! lol), but also gives you a visual history that you can skim through over time. My knowledge of food has taken five or ten years to get where it is today. Right now, I really like IIFYM as a sustainable approach to getting good results while also not going nuts from a restrictive diet. And that works whether you're eating the same thing every day or whether you have a month's worth of variety. My personal preference at this time is to eat a variety of foods, to fit them in my daily macros, and to prepare meals that I look forward to eating. It's so much easier to stick with your diet when (1) you prep your meals ahead of time, and (2) you look forward to eating each meal because it tastes awesome.
Looking forward to eating a meal that has already been made is the best way I've found to be successful (particularly with IIFYM). I have an insulated lunchbox from Isolator Fitness to carry my food with me all day long, plus alarms on my phone for when to eat. Alarm goes off, I pull out a prepared meal, and it's something yummy so I want to eat it vs. going to the nearest fast-food restaurant or vending machine. This sounds simple, but it's literally life-changing. You feel good all day, you get in great shape through food, and you just don't have to worry about questions like "what's for dinner?" anymore.
