Many of the reductions over the past 30 years have been achieved either by reducing the amount of sugar, salt or fat in a product, or by finding an alternative ingredient.
2016年12月四级真题（第二套）阅读 Section C
英语六级真题
The reason is that when carbon is priced, those emissions reductions that are least costly to implement will happen first.
2017年6月六级真题（第一套）阅读 Section B
柯林斯高阶英汉双解学习词典释义
N-COUNT
减少；降低
When there is a reduction in something, it is made smaller.