Engel's law is an observation in economics stating that as income rises, the proportion of income spent on food falls, even if absolute expenditure on food rises. In other words, the income elasticity of demand of food is between 0 and 1.
The law was named after the statistician Ernst Engel (1821–1896).
Engel's law does not imply that food spending remains unchanged as income increases: It suggests that consumers increase their expenditures for food products in percentage terms less than their increases in income.