Rising food prices affect everyone, but the poorest in society are especially vulnerable. Households in the lowest 20 percent income bracket spent more than a fifth of their income on food last year.

Statistics Korea said on Tuesday that the Engel's Coefficient, which measures the proportion of income spent on food, was 20.79 for low-income earners last year, an eight-year high. Their earnings rose less than 3 percent last year, but food prices jumped 4 percent.

On the other hand, the proportion for households in the top 20 percent income bracket was just over 10 percent.