Around 2- 3 million years ago, our ancestors started to use fire to cook their meat and tools to cut it. These small steps were some of the biggest lifestyle changes in human evolution.
Up until then, our ancestors had been ripping into raw meat with their teeth and tearing off huge chunks.
The chimpanzee is our closest primate and will spend up to half of its day chewing its food. It is likely our ancestors would have had to dedicate a large portion of their day also to exercising their jaws to survive – chewing through raw food to tenderise it so it could cut and ground by the teeth and eaten. As a result, our ancestors had large muscular jaws which took up a vast area of the skull.
In contrast, today’s humans have fairly small jaws and this is due to the use of those tools to help cut meat, and cooking to tenderise and soft it. Cutting meat up into more manageable portions meant that our ancestors did not have to spend so long chewing each piece of meat. Combine this with the discovery of fire and cooking to tenderise meat, render fat and connective tissue and thing became a lot more edible! Therefore the process of eating was a quicker one, and the need for muscular jaws lessened as level of chewing diminished.
Taking time away from chewing meat meant that over time the jaw began to reduce in size. This shift also allowed for more room for brain development. So basic tools and fire may have been a contributory in our development, especially of language skill which are associated with the larger brain of the homo sapiens (latin: wise person).
Why we chew our food
Chewing is essential for digestion and survival. Here comes the science bit:
Chewing secretes saliva which aids the breakdown of starches and fats through the enzymes contained within it. The act of chewing also sends neural messages to other parts of the body to begin the digestion process of the food. Digestive enzymes are released in the stomach also which will help break down the food and convert it to energy.
Our ancestors were on to a winner when they discovered the cooking and tools to begin softening and cutting their meat into small portions. The act of cooking allows more nutrients to be accessed from many types of food than can be efficiently done eating raw food alone. And our tools allow us to effiently butcher the best cuts, and then cut them into edible portions at the dinner table!
Wolfing it down!
What this means is, that today we can theoretically spend a lot less time eating to get the nutrients we need into our system. However, that is not strictly the case – there are still processes in your body that need a bit of forewarning to signal that you are eating! they need to receive the signal that it is dinner time – so if you eat too quickly you’ve finished before they can get into gear.
Eating more slowly better for your health and weight!
Eating more slowly, or precisely, chewing a bit more (so the food almost dissolves in your mouth) is shown to have many health benefits – and it is good for the waistline too.
By chewing more, you take longer to finish you meal, your body has a chance to deploy all its signals, enzymes and digestive tricks to ensure you process your meal in an optimal fashion.
Your body is able to take what it needs more efficiently, and more importantly, you will eat less and feel fuller. For example when you eat the same size meal but chew a bit more your stomach has enough time to send it “full” signal to the brain and suppress further appetite. Your stomach also is dealing with smaller matter, so the enzymes and chemical processes work that little bit more extracting all the goodness from your meal.
Devolve to Evolve
So whilst we have evolved and developed cooking and tools to help us eat, our body has not fully caught up, and still appreciates the slower pace of life.
Don’t rush your meals. Take your time. Socialise, talk and savour your food in good company with friends and family. And remember to “chew your food properly” as our mothers would say!