The 42-year-old stylist, who infamously popularised the 'size zero' trend, is said to be eating only 600 calories a day, reported Showbiz spy.
"She's surviving on coffee, nuts and fruit. As soon as she delivered Kai in December, she was back on the scale and plotting her weight loss. She says she has another 10 lbs to go and is starving herself. She'll 'splurge' on yogurt or pick at string cheese," a source said.