There are some eating plans that pop up, get a ton of buzz, and then quickly fade away. And then there are others like the Blue Zone diet that seem to have some serious staying power.

The Blue Zone diet has been compared a lot to the Mediterranean diet, but there are some differences. It’s worth pointing out upfront that the Blue Zone diet is all about longevity. “There are areas in the world that are considered Blue Zones where individuals live well into their 90s and beyond,” explains Vanessa Rissetto, R.D., the CEO and co-founder of Culina Health. The Blue Zone diet was crafted based on what these people eat and how they live.

Nutritionists say it’s also possible to lose weight on the Blue Zone diet, too, if that’s your goal. (More on that in a moment.)

Meet the experts: Vanessa Rissetto, R.D., is the CEO and co-founder of Culina Health; Keri Gans, R.D., a nutritionist and author of The Small Change Diet; Jessica Cording, R.D., is the author of The Little Book of Game-Changers.

But what is the Blue Zone diet, exactly, and what can you eat on it? Experts break it down.

What is the Blue Zone diet?

The Blue Zone diet focuses on the lifestyles and eating plans of people in parts of the world who live the longest.

The diet was created by journalist, National Geographic Fellow, and explorer Dan Buettner, who wrote the book, The Blue Zones Solution: Eating and Living Like the World’s Healthiest People. In his book, Buettner detailed the diets of people living in these areas and found that, in general, they ate a lot of plant-based and whole, unprocessed foods.

“It’s very high in plant food and very low in meat,” says Jessica Cording, R.D., the author of The Little Book of Game-Changers.

Where are the Blue Zones?

The Blue Zones are five areas of the world where people live the longest. They include:

• Okinawa, Japan
• Sardinia, Italy
• Nicoya, Costa Rica
• Icaria, Greece
• Loma Linda, California

Is the Blue Zone diet healthy?

Yes, nutritionists say this is a healthy eating plan. “We know from research that having a lot of plant foods in your diet has been associated with decreased disease risk,” Cording says. “When you’re having a lot of plants, you’re getting more fiber.” The diet is also high in antioxidants, which have been linked to a lowered risk of several diseases like cancer and heart disease, she says. “There are a lot of health benefits to eating a plant-heavy diet like this, Cording says.

Is the Blue Zone diet the same as the Mediterranean diet?

Not exactly. “It’s very similar to the Mediterranean diet, but there are differences,” Cording says. A big one is that the Mediterranean diet just focuses on the Mediterranean region of the world, she says—this diet focuses on the five different Blue Zones.

“What’s also different from a traditional Mediterranean diet is that it’s much lower in fish, eggs, and dairy,” Cording says. “It’s mostly plant-based. There’s very little meat, very little dairy, very little sugar, and virtually no processed foods.”

What foods can you eat on the Blue Zone diet?

There are a lot of different foods you can eat on the Blue Zone diet. In general, “this is a diet composed of mainly vegetables, fruits, grains, and legumes, with a very limited intake of meat, dairy, sugary foods or drinks, and overly processed food,” says Keri Gans, R.D., a nutritionist and author of The Small Change Diet.

The Blue Zone diet has 11 general guidelines that followers are encouraged to stick to. Here’s a breakdown:

• Limit meat to five times a month
• Make your diet 95% to 100% plant-based
• Reduce your dairy consumption
• Eat no more than seven teaspoons of added sugar a day
• Have no more than three eggs a week
• Eat less than three ounces of fish, three times a week
• Snack on one to two handfuls of nuts a day
• Drink about seven glasses of water a day (and have coffee, tea, and wine in moderation)
• Consume ½ to 1 cup of beans a day
• Fill your plate with single-ingredient, raw, cooked, ground, or fermented whole foods
• Stop eating when you’re almost full, but not stuffed

But the diet also recommends focusing on the following foods:

• Beans
• Sourdough or whole wheat bread
• Leafy greens (including spinach, kale, chard, and collard greens)
• Seasonal fruits and vegetables
• Whole grains
• Olive oil
• Yams and sweet potatoes
• Nuts (pistachio, almond, Brazil nuts, peanuts, cashews, and walnuts)
• Seeds
• Goat’s and sheep’s milk

“Plants are minimally processed and they are generally high in fiber, which helps with maintaining a healthy weight, and boosts immunity, and gut health,” Rissetto says. “Nuts are a good source of omega [fatty acids] and protein.”

Beans, she points out, are also a “great alternative to meat” while fish is a “minimally processed animal protein.”

The sourdough bread aspect seems random, but Cording says it has a potential benefit for your digestive system. “The fermentation process that occurs during the making of sourdough is thought to help make the bread a little easier to digest,” she says. “You’re not taxing the digestive system with sourdough bread.”

What foods should you avoid on the Blue Zone diet?

The Blue Zone diet doesn’t say that any foods are completely off the table, but it encourages followers to limit how much they have of these:

• Added sugar
• Dairy
• Meat
• Eggs
• Fish

Lifestyle habits on the Blue Zone diet?

The Blue Zone diet isn’t just an eating plan—it also encourages certain lifestyle habits. Those include:

• Stop eating when you’re almost full, but not stuffed
• Get daily movement
• Have a purpose
• Build a “tribe” of loved ones around you
• Downshift your thinking (i.e. relax more)
• Put your loved ones first

Can you lose weight on the Blue Zone diet?

It’s important to point out that weight loss isn’t a big focus of the Blue Zone diet. Instead, the messaging around the diet stresses longevity, happiness, and good nutrition.

That said, it’s possible to lose weight on this diet. Cording says that emphasis on eating until you’re full—but not stuffed—can help with portion control, while plant-based diets can be helpful for weight loss and weight management.

The diet is also high in fiber, which can help fill you up and prevent overeating, Cording says. Overall, though, what you were eating before you went on the diet and what kind of portions you have on it matter, she says.

Are there any downsides to the Blue Zone diet?

In general, nutritionists say this is a healthy eating plan, but there are some caveats to keep in mind. “As a registered dietitian, I’m not completely on board with the idea that every person needs to have fewer than three eggs per week and have very minimal dairy,” Cording says. “Those are foods that offer a lot of important nutrients.”

Cording also points out that the diet is “based in observational research” and hasn’t been proven to actually extend your life in clinical trials.

But if you’re interested in trying out the Blue Zone diet, experts say there’s no reason not to. “This type of eating is definitely healthy,” Gans says.