Question

Thin as he looks, he eats a lot. (pattern contrary to common sense) CCP 18

Accepted Answer

别看他瘦，其实吃得不少。别看~，其实~ used to indicate that the actual situation is contrary to what one would think according to common sense. 其实 can be replaced by 但，却，可 or other words that indicate a turn or transition.

Front	Thin as he looks, he eats a lot. (pattern contrary to common sense)
Back	别看他瘦，其实吃得不少。别看~，其实~ used to indicate that the actual situation is contrary to what one would think according to common sense. 其实 can be replaced by 但，却，可 or other words that indicate a turn or transition.
Page	CCP 18

Contrary Common Thin Eats Lot Pattern Sense 别看他瘦，其实吃得不少