I believe "the simpler - the better" formula works in most cases. I don't follow any particular diet, but I do listen to my body and its needs, and I watch how it reacts to everything I consume.

At this point I try to eat natural foods with no artificial colors, hormones, preservatives, etc. They are more expensive, but I don't eat loads, and I don't buy "fancy" food like expensive cheeses, meats, or wines, so I save on that to buy cleaner, more natural stuff.

I cut down on red meat (not because of moral issues; I just kind of don't want it much anymore). Lots of grains, mushrooms, nuts, bread, and vegetables.

I do eat junk food once a week or so. I can have an occasional soda. But (!) I consider this to be just another form of training for my body and mind. For instance, if I eat a load of junk food, sweet bread, etc., instead of lying down or relaxing after that I engage in some heavy mental or physical activity. No, not to burn calories, but to challenge my body and brain. OK, I ate some food that made me sleepy, lazy, and wanting to just sit on the couch and watch my favorite series... But what if I get up and do a 20-minute headstand instead? This way we get stronger... not stronger in terms of muscle power and all that (although that probably as well) but in terms of how our will-power works with the organism.

We all are built and function in a similar manner, but every single organism is so unique that I think most general formulas of how to eat, sleep, exercise, etc., HAVE to be adjusted to the particular needs to that specific person. For example, many scientists say that an average adult needs 6-7 hours of sleep every day, but I am perfectly fine with 4-5 hours. I figured that out through practice. I would never advice this particular sleep pattern to anyone else; what's good for me might be a total disaster to someone different.