Chunky monkeys at an animal park in Japan have been put on a crash diet to help them slim down.
The animals have been piling on the pounds for the last few years, and now some of them are too fat to move around.
It's thought park visitors feeding them tasty treats on top of their normal meals are to blame.
Park officials have swapped the monkeys' fave food of potato with wheat, to help them shift the weight.
About 50 of the Rhesus monkeys live together in an enclosure at the park in Osaka, in western Japan.
Park officials weighed them last year and found some of them were three times heavier than normal adult monkeys.
They think visitors must have been feeding them, despite signs telling them not to.