someone's eyes are bigger than their stomach
US /ˈsʌm.wʌnz aɪz ɑːr ˈbɪɡ.ər ðæn ðer ˈstʌm.ək/
UK /ˈsʌm.wʌnz aɪz ɑːr ˈbɪɡ.ər ðæn ðer ˈstʌm.ək/

1.
眼睛比肚子大, 贪多嚼不烂
to take more food than one can actually eat
:
•
He ordered three main courses, but his eyes were bigger than his stomach.
他点了三道主菜,但他的眼睛比肚子大。
•
I think my eyes were bigger than my stomach when I filled my plate at the buffet.
我想我在自助餐时盛盘子的时候,我的眼睛比肚子大。