thin person who eats a lot; big eater who stays thin
Describes someone who remains slim despite eating large amounts. Often used with a sense of surprise or admiration.
She's a big eater who stays thin, and always orders a large portion.
That person is a thin big eater, so no matter how much they eat, they don't gain weight.
Standard kanji spelling for this set phrase.
Katakana spelling sometimes used for emphasis or in casual writing.
A set phrase combining 痩せ (thinness) and 大食い (big eater). The exact origin is uncertain, but it likely arose from the common observation that some thin people eat surprisingly large amounts.