The federal food stamp program was established in 1964 and in January 1971, Congress redefined the term 'household' so as to include only groups of related individuals. The Secretary of Agriculture promulgated regulations rendering ineligible for participation in the program any 'household' whose members are not 'all related to each other.' Appellee Jacinta Moreno, for example, is a 56-year-old diabetic who lives with Ermina Sanchez and the latter's three children. They share common living expenses, and Mrs. Sanchez helps to care for appellee. Appellee's monthly income, derived from public assistance, is $75; Mrs. Sanchez receives $133 per month from public assistance. The household pays $135 per month for rent, gas, and electricity, of which appellee pays $50. Appellee spends $10 per month for transportation to a hospital for regular visits, and $5 per month for laundry. That leaves her $10 per month for food and other necessities. Appellee has been denied federal food assistance solely because she is unrelated to the other members of her household. Mrs. Sanchez and her three children were permitted to purchase $108 worth of food stamps per month for $18, their participation in the program will be terminated if appellee Moreno continues to live with them. The District Court held that the 'unrelated person' provision of § 3(e) creates an irrational classification in violation of the equal protection component of the Due Process Clause of the Fifth Amendment.