In the absence of special instructions, inflation is generally measured by the consumer price index (CPI), which is mainly because CPI is a price index compiled by deducting the weight according to the commodity types of consumers' final consumption expenditure in a country, which most directly affects the real purchasing power of residents' income, No price index is more appropriate and considerate of public opinion than CPI. The fluctuation of food price dominates the fluctuation of China's consumer price index, not only because food price accounts for more than 30% of the commodity basket, but also because food price itself fluctuates violently. 
paying attention to food price fluctuation has become the top priority in the study of China's inflation.
Explain how food price fluctuations affect the consumer price index