there’s an episode with a guy from the UFC training center and in it they mention a MMA who’s always on keto

Yes—the episode is How to Exercise for Strength Gains & Hormone Optimization | Dr. Duncan French, featuring Dr. Duncan French, Vice President of Performance at the UFC Performance Institute. 1

French mentions UFC fighter Matt Brown as an example of someone who promotes a ketogenic approach and says it works for him. He explains that the UFC’s strategy for some athletes is to eat largely ketogenic-style meals while timing carbohydrates around training—before, during, and after—to support the high-intensity demands of MMA. 2 3