"fatten up" in Chinese (Simplified)
养肥
Definition
通过给某人或某物比平常更多的食物，使其长胖。常用于动物在出售或食用前，也可以幽默地用在人身上。
Usage Notes (Chinese (Simplified))
非正式，常带玩笑或亲昵的语气。多用于动物（如“养肥猪”），在形容人时也有幽默意味。不会用于严肃或医学语境中讨论体重。
Examples
We need to fatten up the chickens before winter.
我们需要在冬天前**养肥**这些鸡。
Grandma tries to fatten up her grandchildren with cookies.
奶奶用饼干想**养胖**她的孙子孙女。
Farmers fatten up cows before selling them.
农民在卖掉牛之前会**养肥**它们。
You've lost weight! Let me fatten you up with a good meal.
你瘦了！让我给你做好吃的来**养养你好了**。
They serve huge portions at that restaurant to fatten up their customers.
那家餐厅上的份量很大，是想把顾客**养胖**。
The bear needs to fatten up before hibernation.
熊在冬眠前需要**养肥**自己。