Minecraft wiki entry for Pufferfish_(item), associated text: Pufferfish restores 1 () and 0.2 saturation, but inflicts Hunger III for 15 seconds, Poison IV‌[Bedrock Edition only][1] for 1 minute or Poison II‌[Java Edition only] for 1 minute, and Nausea I for 15 seconds‌[Java Edition only] or Nausea II for 15 seconds‌[Bedrock Edition only][2]. Unlike rotten flesh, it is not helpful to eat pufferfish while starving because they inflict more hunger than they earn.