Asked by Kim Bridges
Meat can harbour many different bacteria, viruses and even parasites. Cooking meat properly destroys them, making meat much safer for consumption. Bacteria and viruses can easily make you ill, while parasites can grow inside your gut and even migrate to your brain. Food poisoning is a very serious business and by not cooking meat thoroughly, you are greatly increasing your chances of getting something nasty. People quite often eat raw meat such as steak tartare, but it requires extra care in the preparation.
Besides safety, cooking meat also makes it taste better, not to mention easier to chew and digest. By cooking meat and other foods, humans can get much more energy than from chewing on raw food alone.
José Monteiro, Science Museum Explainer