Statistical relationships called expenditure elasticities are detailed for 24 major food groups and 77 subgroups. They allow researchers and policymakers to anticipate what can happen to family expenditures for these foods when income and household size change. The elasticities generally confirm that spending for food away from home increases significantly as income rises while spending for food prepared at home increases more modestly. The reverse relationship is true for increases in household size. The elasticitiy coefficients established here are based on the U.S. Department of Agriculture's 1977-78 Nationwide Food Consumption Survey.