Showtime's Fat Actress is suffering from anorexic ratings. After debuting with a decent 924,000 viewers last week, the Kirstie Alley comedy purged 70 percent of its audience in its second outing Monday, averaging just 285,000 viewers. The news was better for HBO's [bleepin'] brilliant Deadwood, which drew 3.41 million viewers Sunday night — a 22 percent build over last week's second-season premiere. And with Glenn Close's help, The Shield kicked off its fourth season Tuesday with 3.9 million viewers, up 37 percent over its Season 3 opener.