My performance (and weight) is entirely unaffected by my nutrition and training

Reading this post it seems like you're at a healthy weight for you but you think your weight is deterring your progress. You didnt mention your height that I saw but at your listed weight and your body fat percentage I fail to see why that would be unhealthy or deterring you from your progress. Your listed diet makes it seem like you get enough carbs, fats, and proteins to be recovering and re building your muscles. It might be worthwhile for you to explore other avenues besides weight loss to increase performance. Probably the best thing to do if you haven't would be to go see a doctor and get labs done to see if anything is out of balance that won't allow you to progress (low testosterone, low vitamin levels), if something is acting up it will impact all your other systems as well. Other than that you said mobility and stability work but didnt mention specific strength training at all, more muscle could help you out as well.

/r/AdvancedRunning Thread