I'm not a tennis fan so can't comment on that, but the sport I follow has a massive history eating disorders, food restriction, and coaches actively taking food from athletes. I'm not saying Kate does or doesn't have issues with food, but you can't say that her athletic body proves she doesn't.
I am guessing you follow gymnastics and/or figure skating from those comments? Sports where maintaining a pre-pubescent body shape for as long as possible helps massively with the physics involved in performing elite skills? Not all women’s sports are like that any more.
And also, the goalposts are being moved slightly. People have been commenting how Kate starves herself. Her muscle tone shows she does not starve herself: she self-evidentially consumes enough calories to build and maintain muscle. No-one knows whether she has other “issues with food” as you put it.