The Dutch star has scrubbed steak off the menu - because he thinks too much meat will affect his muscles.
Van Persie told The Sun: "Someone told me too much meat has a negative influence on muscles. I was a big meat eater and had steak three times a week.
"Now I only eat meat once in the week and never a day before the match. I spoke about it with Kolo (Toure) as he also had meat every day.
"He stopped immediately and since then he hasn't had any muscle problems."
Van Persie has played 34 games this season and will spearhead the Gunners attack in their Champions League last-16 second leg at Roma tonight.
But the Dutchman's recent campaigns have been ruined by injury.
Van Persie added: "I'm always learning more about my body. Many people underestimate how important diet is. Now I have fish and pasta.
"This is a small thing that can improve my game.
"Because of the injuries I've had, everything helps.
"I'm learning and listening to my body."