Tbf, I'd probably eat that amount of calories if I were looking to drop some weight, and I weigh significantly less than 20 stone. It really does depend on how "active" you say you are, and how much you are looking to lose each week. We all know she's a slow loser 
Jeeeez... That belt looks tight as anything
Must be painful. Looks tighter than her resistance bands
Jeeeez... That belt looks tight as anything
Must be painful. Looks tighter than her resistance bands