ガタイ (がたい, gatai) Japanese meaning: body build | KotomoraExpressions
ガタイがいいbig and brawny; well-built; gigantic がたいのいいbig and brawny; well-built; gigantic
。
He has a big build, so he's suited for physical labor.
Hiragana spelling is also used, but katakana is more common.
Etymology
The exact origin is uncertain, but it may be a slang alteration of 体 (からだ) or related to がっちり (stocky, solid).