At the times in which cavemen lived which was roughly '2.5 million years ago' [Stone Age] people ate food such as eggs. Cavemen got eggs from the nests that were easy to get eggs from and cavemen ate them raw!Cavemen used spears to catch big fish such as Salmon not only fish but Mussels and Clams and Shellfish were eaten to. They could eat Nuts that were ready to eat at Summer and Fall and since the climate changed they knew what climate it is supposed to be in order to go gather some nuts.
About forty thousand years ago people already ate fruit and some were amazingly similar to the fruits we eat now. For example some figs was found in the North part of Israel that was 780,000 years old! There were not only figs but also there were a number of olives, plums and pears! Also some archaeologists and researchers in the north part of Tennessee found grapes that were 7 million years old! Apples trees were in Kazakhstan 30,000 years ago. People at those times also ate oranges that were found in China and wild berries were eaten in Europe! Most of these fruits were not exactly the same, some were similar some not but in either way they were edible.
Ancient civilizations such as the roman empire ate foods such as garlic, leeks, onions, rosemary, thyme, bay leaf, basil, shallots, cabbage, peas, celery, turnips, radishes, honey, porridge, pancakes. Ancient civilizations also ate flying animals for meat such as pigeon, quail, goose, heron, and duck. The ancient civilizations also ate bread and eggs. They didn't have processed food like chips but they did have some of the foods that we still eat today! In those times it might have been that it was a better diet since there were no processed foods so all of the food was either natural or made out of bread.
Now we have a huge variety of food such as tomato, vegetables, burgers, cooked food, diary products. There are so much stuff some we grow unlike people in the pre civilization time some foods we make either by changing genes or by making processed foods that are not natural such as chips, coke, lemonade, energy drinks, gummy food, onion rings, doughnuts, cupcake, and a huge variety of candy and many other sweets. These processed food gave us plusses and minuses for example in Ancient Civilization you couldn't grab yourself a cookie or two for a snack and you had to carry a whole lunch with you for each time you eat. But most of the processed foods are bad or even dangerous for your body!