In the 1944 case of Carolene Products Co. et al. v. United States, the U.S Supreme Court upheld a federal law that prohibited shipment in interstate commerce of "filled milk" (skimmed milk compounded with any fat or oil other than milk fat, so as to resemble milk or cream). The court ruled that Congress had a rational basis for believing that filled milk was injurious to public health and thus could regulate its sale under the Commerce Clause. This decision is notable for containing Footnote Four, which suggested stricter judicial scrutiny should be applied to legislation aimed at particular religious, national and racial minorities; this footnote has been influential in later cases involving civil liberties and rights.

In the dissenting opinion for Carolene Products Co. et al. v. United States, Justice Robert H. Jackson disagreed with the majority's decision to uphold a federal law banning filled milk products as it was deemed injurious to public health and welfare. He argued that this case should not be decided on its merits but rather sent back to lower courts for further fact-finding about whether filled milk is indeed harmful or unsafe for consumption, which he believed was still an open question scientifically and medically at that time in 1944. Furthermore, he expressed concern over potential government overreach into regulating commerce based on questionable scientific evidence or popular prejudice against certain types of food products without clear proof of harm.