Starting in March, Lewis will be responsible for running the new The National Magazine Company/Rodale International joint venture, which was finalised in May, as an independent business. The venture's titles, Men's Health and Runner's World, will be under her direct control.
Lewis's career has spanned both magazine publishing and television. Before working at Hachette, she was the publishing director of IPC Media's women's group.
She earlier worked with Flextech and the BBC to launch the UK TV channels UK Style, UK Drama and UK Play.
Meanwhile, Ralph Boon, the publishing director of Men's Health, has left the title after ten years. He is taking a sabbatical, but is planning to return to the business by the end of the year.