Why don't overweight celebrities have double chins?

I know I'm probably the only person who thinks so, but sometimes Kath and Kim cracks me up. Case in point: Kim is freaking out about the cable being out because "there is a Denise Richards marathon on at 3 pm and she's right. It IS complicated." Ah.. guilty pleasures. I really miss that show. I don't feel good about it, but it's true.