But you have asbolutely no idea what Lizzo eats or what her weight is related to. She's not advocating for junk food or unlimited ice cream. She's advocating for being comfortable in your own skin, whatever that may be. What the outcry is about is that she is not sufficiently ashamed of her body as it is. That's the entire problem. Even if you plan to work on yourself in some way, it serves no real beneficial purpose to anyone to loathe yourself the way you are now - which is what these people (and you) are apparently demanding.
The fact that you don't believe medical and scientific experts because it doesn't suit your narrative is immaterial.