Alex Rodriguez’s new diet apparently consists of healthy foods and leggy brunettes. The Yankee slugger was joined by an “attractive dark-haired female” at the Delano in South Beach on Saturday. While Rodriguez ordered a virtuous lunch of brown rice, broccoli and chicken, his date unabashedly snacked on less healthy fare. He later headed to Prime 112 Steakhouse that night. Sources tell us A-Rod, who usually prefers the company of buff blondes including Cameron Diaz, Madonna and his trainer Ella Magers, had dinner with an “extremely sexy and feminine tan-skinned brunette.” Rodriguez left alone, walking through a cluster of photographers; the brunette left 10 minutes later. His rep didn’t get back to us.