promising 是动名词,是一种伴随的状态。promising to make you lose weight quickly是product 的定语。相当于the product that promises to make you lose weight quickly.所以这句翻译过来就是:不要被那些承诺可以快速减掉体重的商品所欺骗。
其实这是一个缩写的句子Don't be taken in by sth,这是一个句子,意思是不要被xxx蒙骗。问题中product后面的是定语。完整的应该是Don't be taken in by product which promises to make you lose weight quickly这里可以省略的,把which省略掉