We have no idea what she eats, or how much/little, but whatever it is, I’m sure it’s a very healthy option.
If she had an eating disorder, I don’t think she would look so well, especially after having cancer and being in remission.
Her hair always looks thick and glossy, her skin smooth and a good colour (although I realise she will have the best of hairdressers and make up artists to achieve all that).
I’m sure she is careful about what she eats, but probably has a personal trainer as well. She knows that looking good is part of her role, shallow as that may be.
If she started packing on the pounds, the public would soon turn on her as being another Fergie (cruelly known as the Duchess of Pork at one stage).