I wonder if Grangela's storyline wasn't faked or manipulated. I'm not sure if we actually saw her eat any of the solid food in the soup. She did smoke, though, so it could well be that the smoking and eating was filmed long before the surgery.
Of course, she could actually be stupid enough to eat solid food before surgery. Smoking is a risk factor for any surgery, but for the habit itself, not so much for the day of surgery as far as I know.