Rihanna's busy career is making her too skinny.

"My schedule is crazy!" she recently told Us Weekly. "It's harsh on your body!"

So harsh, in fact, that RiRi has dropped some serious weight in recent months.

"I'm a size 0 -- and not happy about it!" she says. "I went way too far. I prefer myself a bit chunkier. I want my old butt back!"

A few others seem to want it back too. *rimshot*