We might need to define "unhealthy" here. Mine is going to be different from other people's.

Regarding food, I believe the pop definition of "unhealthy" is wrong. As far as I can tell, after having worked in the food industry on the regulatory side, and after having tried to understand nutrition from a truly scientific standpoint, the biggest goof people make is portion size, and, less commonly, having too "small" a pool of foods they'll eat so certain vitamins/minerals are lacking. The rest of it with added sugars or fat or this or that ingredient being "bad" is smoke and mirrors. Portion size is really, really, really fucking important.

You can be healthy eating just about anything (even McDonald's) as long as the portions are appropriate for your size and amount of exercise, and so long as your diet is varied enough overall to bring in enough vitamins and minerals. So, eating 3 super-sized meals at McDonald's might screw you up because the calories are too much for your level of activity, but if you scale it back to 1 a day and keep the meal size "small", or even eat a happy meal as an adult, you'll be ok.

Regarding vitamins and minerals...in the modern day, people tend to be deficient in vitamin D because they don't get enough sun, so that sometimes needs to be supplemented. And individuals will sometimes be deficient in iron or vitamin C. I supplement with C because I tend not to eat many foods with it, and D because I'm a vampire-like nerd that stays away from the sun.

Anyway. To get back to the question, I basically eat what I want, without regard for whether pop culture thinks it's bad or not, but I pay attention to portion size and I do not snack. I've sometimes fallen into keto behaviors or one-meal-a-day but I don't follow either with any dedication, my natural patterns just fall close to those.

Do I sometimes buy and eat things that are unhealthy for me? Well, by MY standards...not really. I understand nutrition, and I understand portion sizes, and it's not all that hard for me to eat appropriately for my size without worrying about whatever the latest health food fads are blabbing on about. And because I understand what I'm doing, and I have control of it, I don't feel guilt.