One Piece

The Binge Binge no Mi, or Feast Feast Fruit, is a meatball-shaped Devil Fruit that grants its user the ability to convert calories from consumed food into enhanced physical stats. The user can boost their strength, speed, durability, and Haki potency based on the type and amount of food consumed, but must maintain a high caloric intake to avoid severe penalties. If the user does not eat at least 20,000 calories per day, they enter "Brittle Bone Mode": All bones become fragile as glass.