If you can’t tell a spoon from a ladle, then you’re fat!

The joke hinges on an absurd “diagnostic” for being overweight: confusing a spoon with a ladle. Since a ladle is essentially an oversized spoon, the punchline implies that only someone accustomed to very large portions—or needing a larger utensil to eat—would lose the ability to distinguish the two. Martin’s humor often works by taking a familiar category distinction and collapsing it into a blunt, mock-authoritative rule. The line also parodies the way people sometimes reduce complex realities (like body size and health) to simplistic, supposedly obvious indicators, exposing the cruelty and illogic of such snap judgments through exaggeration.