The web site, which operates as a licensee of dieting body Weight Watchers International, is to provide back-up to people who are unable to attend Weight Watchers meetings.
Hilton will be responsible for areas including advertising, e-CRM, PR and research. He joined last month to replace Julie Philpott, who has left to go travelling.
His first task will be to strengthen the site's relationships with major portals, ensuring partnerships are profitable for both parties.
He will widen the reach of the brand to other ISPs and portals, including female-specific offerings such as handbag.com, and will look to increase user numbers.
Hilton left online gaming site MGM in August when the company pulled out of the UK. Prior to MGM, he launched Workthing.com, Guardian Media Group's online recruitment brand.