Humans had larger skulls and stronger jaws before they started consuming dairy products, according to a study undertaken by researchers at the University of California.
The study's authors claim: "The advent of farming, especially dairy products, had a small but significant effect on the shape of human skulls."
Professor Tim Weaver, statistician Mark Grote and anthropologist David Katz made the discovery after measuring specific points on more than 500 human skull bones.
According to the research, the change all comes down to chewing.
The report says: "Humans who live by hunting and foraging wild foods have to put more effort into chewing than people living from farming, who eat a softer diet.
"Although previous studies have linked skull shape to agriculture and softer foods, it has proved difficult to determine the extent and consistency of these changes at a global scale."
The scientists discovered 'the most significant changes in skull morphology groups consuming dairy products - suggesting that the effect of agriculture on skull morphology was greatest in populations consuming the softest food - i.e. cheese'.
Katz, who is now a postdoctoral researcher at the University of Calgary, Alberta, said: "The main differences between forager and farmer skulls are where we would expect to find them, and change in ways we might expect them to, if chewing demands decreased in farming group.
"At least in early farmers, milk did not make for bigger, stronger skull bones."