Invert their food pyramid and have the truth.

Tons of sweets, got it

[eat] Fat, Meat, Cheese, Bread, Sugar [limit]

The only thing we ate plants for was already in the dirt. We can get all that ourselves. I consider fruit a dessert item. I don't eat refined sugar.

Nutrition and Physical Degeneration: A Comparison of Primitive and Modern Diets and Their Effects by Weston A. Price

An epic study demonstrating the importance of whole food nutrition, and the degeneration and destruction that comes from a diet of processed foods.

For nearly 10 years, Weston Price and his wife traveled around the world in search of the secret to health. Instead of looking at people afflicted with disease symptoms, this highly-respected dentist and dental researcher chose to focus on healthy individuals, and challenged himself to understand how they achieved such amazing health. Dr. Price traveled to hundreds of cities in a total of 14 different countries in his search to find healthy people. He investigated some of the most remote areas in the world. He observed perfect dental arches, minimal tooth decay, high immunity to tuberculosis and overall excellent health in those groups of people who ate their indigenous foods. He found when these people were introduced to modernized foods, such as white flour, white sugar, refined vegetable oils and canned goods, signs of degeneration quickly became quite evident. Dental caries, deformed jaw structures, crooked teeth, arthritis and a low immunity to tuberculosis became rampant amongst them. Dr. Price documented this ancestral wisdom including hundreds of photos in his book, Nutrition and Physical Degeneration.

Life-changing book. Everything you're asking about is in there. In short: look up your pre-industrialization racial ancestral diets, and eat that.