The simple unprocessed daily diet of a Blue Zone nutrition expert, meal by meal

• Professor Joan Sabaté has spent decades studying how eating plants impacts our health.
• He's discovered some serious health benefits linked to nut, berry, and avocado consumption. 
• His daily diet prioritizes fresh produce, while avoiding ultra-processed fare.

Joan Sabaté is admittedly "nutty" about good health and nutrition.

Not only does he live in America's only longevity "Blue Zone," this nutrition buff and director of the Center for Nutrition, Lifestyle and Disease Prevention at Loma Linda University has also spent decades investigating how different foods — especially unprocessed plants — can influence health.

In the 1990s, he was the first nutrition researcher to discover that while walnuts contain small amounts of saturated fat, they are actually good for your heart — a finding that surprised him, and upended American Heart Association recommendations. Later, he helped author the 2020-2025 Dietary Guidelines for Americans.

He understands that healthy eating isn't only about achieving the right balance of macronutrients — protein, carbs, and fat — but that there is a bigger "total package" of nutrition benefits that are naturally occurring in foods like whole grains, beans, and vegetables.

Already, he's found compelling evidence that nuts, beans, avocados, and berries are all health-boosting foods that can lower the odds of developing chronic diseases like diabetes, obesity, and heart issues.

He is now investigating how certain plant foods might impact our immune system, potentially enhancing the body's ability to fight off infections like the common cold or COVID.

"I think there are, in many plant foods, still things that have to be studied and discovered," he said.

He shared his general practices for breakfast, lunch, and dinner with Business Insider while admitting that his diet "is not sophisticated," and mainly involves avoiding ultra-processed foods.

Breakfast is a two-ingredient 'smoothie' made from leftovers

Sabaté always likes to keep nuts like walnuts, almonds, and hazelnuts around the house, and he puts a few handfuls into his blender each morning, along with about two cups of whatever fruit happens to be the ripest on his Southern California table. This is an easy way for him to quickly get a couple of servings of vitamin-rich fruit and a couple of servings of protein-heavy nuts into his day.

It's not always the most photogenic meal, but he doesn't mind, because he's not "showing off" this breakfast to any friends or colleagues.

"No, I eat this at home," he said.

Sometimes, the mix is too thick to pour into a glass and he eats this "smoothie" with a bowl and spoon while he's getting ready to tackle his day. Occasionally, he'll add a plop of yogurt or sprinkling of cacao nibs on top.

Lunch is three core ingredients, plus olive oil

In traditional Spanish fashion, the biggest meal of Sabaté's day is usually lunch, where "we eat a pot of beans."

One of his favorites is "a typical Catalan dish that is beans and broccoli," but he likes to sample a wide variety of beans to keep things interesting.

"In the Loma Linda market there are at least 20 different types of beans," he said.

At its essence, his lunch is always "a legume, a vegetable, and then bread."

"Mediteranneans, we love bread — bread with olive oil," Sabaté said.

Scientists suspect that one of the key reasons that Mediterranean diets are so often associated with long, healthy lives and strong minds is because they're loaded with olive oil, which has long been associated with better heart health, fewer type 2 diabetes cases, less inflammation, and lower overall mortality.

Dinner is usually pretty insignificant, but if he goes out to eat, he might have some fish

For Sabaté and his wife, dinner is typically an afterthought.

"We try to have either no supper or light supper," he said.

If breakfast is hearty enough, he'll do a late lunch and perhaps skip having a third meal altogether. Other days, dinner is "maybe a salad, and that's it."

Leafy salad greens are great for your gut, and they're loaded with nutrients like vitamins A, C, and K, as well as plenty of fiber and magnesium.

At home, his meal plan is generally vegetarian and fairly low-dairy, but Sabaté isn't opposed to having some omega-3-rich fish when he goes out to eat. Vitamin B12 is an essential nutrient that we can typically only get from animal products like meat, eggs, dairy, or fish. Vegetarians and vegans can supplement their diet with pills or try algae.