How do anorexics lose weight?

I’m not in any way interested in becoming anorexic. I’ve been down that road and am still recovering.

I just never understood how they lose so much weight so quickly. When you starve yourself your body goes into “starvation mode” which causes your body to hold on to everything, not burn it as it normally would. So what’s the deal? They’re in this “starvation mode” yet they still lose weight. Does anyone happen to know why?