The researchers estimate that such a diet would have saved early humans as many as 2.5 million chews per year, and made possible further changes that helped make us human.
One of the biggest puzzles in human evolution is how species such as Homo erectus evolved smaller teeth, smaller faces, and smaller guts, and yet managed to get more energy from food to pay for their bigger brains and bodies before cooking was invented.

"What we showed is that by processing food, especially meat, before eating it, humans not only decrease the effort needed to chew it, but also chew it much more effectively" said first author Katie Zink, a lecturer at Harvard University in US.

By changing their diets to include just 33 percent meat, and processing their food - slicing meat and pounding vegetables - before eating, researchers found that the muscular effort required per chew and the number of chews required per day was reduced by almost 20 percent.

They also found that by simply slicing meat with the sorts of simple tools available more than 2 million years ago, humans were able to swallow smaller, more easily digestible pieces than would have been possible without using tools.

Latest News from Lifestyle News Desk