Kirby: Right Back at Ya! - Season 1 Episode 61 Fitness Fiend
Overview: King Dedede wishes for a snack and suddenly comes across a box of chips intended for Kirby. Thinking they are tasty, he eats several bags of the chips to have himself become obese as well as Kirby. To make them fit again, King Dedede hires a monster named Max Flexer who gives effective, yet painful workouts.