[译] 节食以后，她变成一个身材苗条的姑娘了。
[误] After being on a diet, she got a thin girl.

[正] After being on a diet, she got a slim girl.
[注] 形容词 thin 意为"消瘦的"，含有贬义，如：She is a thin old woman. 她是一位瘦削的老妇人。slim 与 slender 有"苗条的"之意，用于褒义，如：All girls want to be slender. 个个姑娘都想身材苗条。