In an interview with the Telegraph, the former Man City player, who is now 33-years-old, credited plant-based food for his 'improved fitness'.
"I hardly eat meat now. Plant-based food makes me feel better," Kompany said.
This isn't the first time a professional footballer has praised a plant-based diet.
Manchester United footballer Chris Smalling has been vocal about his transition into veganism, which he says has increased his 'strength and power'.
In an interview with Sky Sports News, Smalling said: "The second day after a game is often when I feel most fatigued, but my fatigue levels have gone down and, on the second day, I've felt a lot more recovered than previously.
"We did a test of our hamstrings and I've increased by 35 percent from the last test. On the bike, my power output has gone up."
Smalling also noticed an improvement in his skin, commenting: "I had a lot more breakouts before than I do now. I'm feeling a lot of physical benefits from it."