Through fat, I gain weight.

脂肪生体重。

youdao

I gain weight.

我的体重增加了。

youdao

If I gain weight, I won't blame a restaurant.

如果我的体重，我不怪餐厅。

youdao

It sounds like your daughter was naturally thin to begin with, so I imagine that it will be even more challenging to help her gain or maintain weight.

CNN: How can I help my heroin-addicted daughter gain weight?

But one thing I doubt will ever be proved false is that it's much easier not to gain the weight in the first place than to take it off later.

CNN: What you thought you knew about obesity is wrong