Obesity is bad for your health. / 

Being overweight is bad for your health.

过胖对健康是有害的。

You need to gain weight.

你应该增加一些体重。

You don't need to lose weight.

你不需要减肥。

It's bad to starve to lose weight.

透过挨饿来减肥很不好。

I can get fat even from drinking water.

我喝水也会变胖。

My friends call me a fatty.

我的朋友们都叫我胖子。

It's bad to make fun of people for their looks.

取笑别人的外表是不好的。