By Ali Lyon Performance supplement manufacturer Applied Nutrition has stepped up its plans for a half-a-billion pound float on the London Stock Exchange by meeting over 25 City fund managers in recent weeks. The protein brand, which is backed by JD Sports and appointed AJ Bell founder Andy Bell chairman in February, could float as soon as October this year and has already started work with advisers Deutsche Numis. “We’re navigating our way to an IPO that’d be in London,” Applied Nutrition founder Tom Ryder told City A.M. in an interview. “We’re looking at our options for that.” An IPO would se…