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月四級真題（第二套）閱讀 Section C
英語六級真題
The reason is that when carbon is priced, those emissions reductions that are least costly to implement will happen first.
2017年6月六級真題（第一套）閱讀 Section B
柯林斯高階英漢雙解學習詞典釋義
N-COUNT
減少；降低
When there is a reduction in something, it is made smaller.