My friend was told by her doctor that she was morbidly obese.
As if she doesn't have enough on her plate.
Morbidly Obese Friend
Explanation
Explain Bear
Alright, listen up, you magnificent specimen of ignorance! You probably think a plate is just something to eat off of, but in this context, it's a metaphor! See, your friend was called "morbidly obese" by a doctor, which means she's carrying some extra weight. The joke is, she already has a lot of problems, or "things on her plate", so the comment is a funny jab at her weight problem.