Let me start by saying that I'm not a nutritionist or a dietician. I don't have any relevant qualifications. My advice isn't medically sound. I can only tell you what works for me.
I like food. I mean, I really like food. I'm not a fussy eater or one of these people who says "I love sweet things but, otherwise, I can take it or leave it.". I'm a greedy pig. I'll eat a massive dinner then look at the dessert on offer and think "Oooh, I'll just have a little piece of that...and a piece of that...oh screw it, I'll have a bit of everything."
If it wasn't for running, I'd probably be massively overweight. It's one of the main reasons that I keep running - I don't want to stop eating the way that I eat. I don't want to make myself miserable every day by denying myself the things I love. Lots of people argue that this approach isn't as good as just eating well but a) I get so much more out of running than calorie burning and b) I get to continue to enjoy my love of food which, in itself, is healthy - enjoying your vices in a relaxed way has to be better for you than living some miserable, puritanical life of everyday denial. I'm not saying that some people don't enjoy trading coffee for hot water with a slice of lemon and monthly juice cleanses and sprout crumble. I'm sure some do but it's not for me. A friend of mine was once horrified to learn that I'd "ruined" a perfectly good green smoothie with the addition of a jumbo choc ice.
I think it's about balance. I have a desk job which means I sit very still for a lot of the day. Running regularly counteracts some of the health risks of all that sitting. By the same token, my running helps to keep my weight healthy, my blood pressure low and my heart and lungs strong. Of course I'd be healthier overall if I had a job that kept me moving and I ate less meat and fewer sweet things but it's a case of diminishing returns. You can do a lot more worrying about your habits in return for slightly better health, for a few more months or years in your dotage, or you can crack on and enjoy yourself, knowing that you can look back and think:
"I had that burger I wanted. And it was goooood."
As far as the "when" of eating for running goes, I'm an empty stomach kind of a person. If I don't have a good few hours between a meal and a run, I tend to get a stitch. I do some of my best running early in the morning, before breakfast, with only water to fool my body into thinking it's not starving. Perhaps I'm genetically pre-disposed to running on reserves, perhaps it's just habit because I've always run in the morning. Either way I know that, unless I actually feel hungry when I get up, what works for me is to head out and run then scoff down a load of protein and calories when I get back.
Maybe that's not you though. Maybe you're better off having a big bowl of porridge (or a fry up) when you get up and going out later. Maybe it's sufficient for you to have a banana before you leave. Maybe you run best in the evening when you have plenty of available energy from what you've eaten during the day. I don't know, I'm not you, the best thing you can do is to try different things and see what works for you. Try them a few times because we all have good days and bad days and maybe that day you were too hungry to run well even though you'd had a banana was just a particularly hungry day. Over time, you'll find something that works for you and, for the most part, your body will settle into that routine.