Global cooling around the last modern ice age, 2.5 million years ago, meant early humans found fruits and vegetables scarcer to find and helped bring about the adaption of hunting and gathering. This more than anything else evolved our bodies via natural selection to be the way they are today. Archaeology shows early humans learnt to control fire about one million years ago and cooking sites appear frequently around 400,000 years ago. Cooking food enabled us to obtain enough energy to evolve our uniquely large brains and distinguish ourselves from other species through intelligence.
Fossil records show hunter-gatherers were tall, healthy, and with little tooth decay. When not killed by another human or animal, they had a good chance of living into their 7th decade. Just 200,000 years ago, modern humans evolved as hunter-gatherers, eating wild animals for fat and protein with staples of fruit, vegetables, nuts and seeds. The human genome has changed little since. Instead, Cultural Evolution has taken over as the dominant factor of change.