I'm currently reading The Ohlone Way by Malcolm Margolin, which is about the Ohlone Native Americans of the San Francisco Bay Area and Monterey Bay. The book describes the diet of the Ohlone as including many types of meat, including salmon, deer, fowl, abalone, and insects. But the bulk of their diet, their everyday staple, was acorn flour. The Ohlone soaked the acorns to reduce their tannin content, then ground them into flour that they ate for nearly every meal. They even made acorn bread that was described as "rich and oily". The Ohlone were unique because most of the other Native American tribes of North America relied on cereal grains, principally corn, as the staple of their diet (and to a lesser extent, beans and squash).

In other words, the diet of the Ohlone was a presumably moderate-carb diet that relied on nuts and whole animal foods.

We don't have much data on the Ohlone's health, but we do know that they enjoyed a rich social life.