This is a very interesting question. First, I don’t think I’m at a place in my running where diet plays a major role in meeting my goals. My goals are not peak performance-based, being more along the lines of “let’s see what I can do in a marathon when trained” along with, perhaps, some small incremental goals in my half marathon times.
Ultimately, I think a lot of it comes down to whether you “live to run” or “run to live”. In my mind, “living to run” entails tailoring your lifestyle around running performance, setting priorities around running goals and making lifestyle changes to meet them. On the flip side, to me, “running to live” is more along the lines of making running a piece of the lifestyle puzzle, using running to enhance enjoyment of life but not making it a driving factor. There is, of course, a continuum between the two, and individuals may fall anywhere on it. I think we can all identify folks on here that fall in various places on the spectrum.
I consider myself to be somewhere in the middle, but definitely shading towards the “run to live” side. Personally, I want to enjoy my running, not feel like it’s a job. It has, and continues to, help with maintaining weight loss. I tend to view running as a bit of a “calorie sink”. I run not only to pursue general fitness and enjoyment, but also to allow myself to enjoy the foods I love in moderation. As such, I don’t really use the reward system with myself, as I tend to rebel against things like that and say “screw it, I want it”. I think that’s why the niche diets never worked for me, because I found myself craving the things I wasn’t allowed. I found my success with calorie counting where I could eat anything I wanted as long as I can work it into my caloric budget for the day. That’s not to say there aren’t splurge weekends or trips here or there, they are just limited. So, I guess that’s a very long-winded way of saying I don’t change my diet when training and I don’t tie my indulgences to running-based rewards, as I don’t want to create a negative feeling towards running if I don’t meet a set goal.