1> It is probably better,however ,if we spend our time and money in buying good food and keeping a balanced diet . if we eat healthy food in the right amount ,we do not have to buy any supplements .The same goes for “crash diets” that some companies say will make us lose weight fast. 最后一句的go for 本义是什么？the same goes for sth 是不是可以理解为固定句型？是什么意思？最后一句里say 后面的是宾语从句吗？按我的理解say 后面应该有‘they’才是完整的句子，怎么可以省略呢？（从句里怎么可以没有主语呢？）
2> We wanted to fix up the old house . We did try once . But when we tried to whitewash the old walls,the dust fell off the wall as the brush went across it .We ended up with the old walls looking even worse than before. The same goes for keeping a house like that clean.
最后一句里的go for 是什么词义？麻烦你把最后一句翻译一下吧？（like 和clean分别是什么词性啊？）