Two of the oldest known Sumerian written works "Kesh Temple Hymn" and the "Instructions of Shuruppak" date to around 2500 B.C.

I haven't been writing about smart nutrition for that long, but sometimes it feels like it. Nonetheless, I'm always glad to see backup for my life's work with new, high-quality research from scientists interested in long and healthy living.

The latest is a review from the USC Leonard Davis School of Gerontology, published in the journal Cell. It looked at hundreds of studies on nutrition, diseases, and longevity in laboratory animals and humans. They included high-fat and low-carbohydrate ketogenic diets, vegetarian and vegan diets, the Mediterranean diet, and calorie-restricted diets.

The researchers discovered that the best diet for an extended health span and lifespan includes moderate to high carbohydrate intake from non-refined sources, low but sufficient protein mostly from plant-based sources (lots of legumes), and enough plant-based fats to provide about 30% of your energy needs.

Ideally, your day's meals happen in an 11-12 hour window, and every three to four months you go through a five-day cycle of a fasting or quasi-fasting diet. That helps reduce insulin resistance, blood pressure, and other risk factors for chronic diseases.

Sound familiar?

One caution: Once you're over 65, to avoid frailty you should increase your protein consumption and make sure to eat a lot of complex, unrefined carbs.

For more help, check out "What to Eat When" and the "What to Eat When Cookbook" to launch your live-better-younger-and-longer campaign.