Scientists say this diet could save people and the planet. It’s more doable than you think.

Does the world really need another diet? The 70 authors of a 62-page report that came out last year say the world really can’t afford not to go on what they’re calling the Planetary Health Diet.

They argue these dietary guidelines could save 15 million lives a year by preventing diseases like obesity and high cholesterol. These dietary patterns would purportedly also feed 9.6 billion people by 2050 and protect the planet by reducing greenhouse gas emissions—among other benefits.

The report doubled down on the same plant-based, whole-grained, meat-avoidant diet first set out by this group of scientists, the EAT-Lancet Commission, back in 2019.

In the six years since, I’ve wondered how easy the planetary health diet would be to follow. Would I have time for it? Would I actually enjoy the types of meals we should all be eating in a healthier, more sustainable, and more just world?

For one week—Saturday to the following Sunday—I ate whole grains instead of refined grains, consumed way more vegetables than I normally do, cooked most of my meals at home, and avoided red meat. I’ll walk you through how I planned my meals, what I learned while executing it, and what my takeaways were, in case you want to try it too.

The core tenets of the planetary health diet

You only really need to keep a few guiding principles in mind, says Walter Willet, one of the paper’s authors and a food scientist at Harvard.

“It all comes down to something very simple,” he says. “It’s about one serving of dairy a day, and about one serving of another animal source of protein per day, with red meat not being more than once a week.”

Of course, he adds, if you want to follow a vegetarian or vegan diet, that’s more than welcome.

I asked him why not recommend a vegan diet outright, since studies show it’s the most environmentally friendly way to eat.

“We designed it that way to maximize flexibility and make the biggest tent possible,” he answered.

While following this diet, the biggest change for me was following its emphasis on whole grains, which make up the report’s single biggest daily recommended food group. I asked Willett if the whole grains were solely there for fiber and if I could replace them with something like a smattering of chia seeds.

(Learn more about the health benefits of chia seeds.)

Not so much, he said. Whole grains have B vitamins, zinc, iron, and vitamin E that you miss out on if you eat refined grains.

Debbie Fetter, a nutritionist at the University of California, Davis, who was not involved in the Lancet report, broke down why.

“When it comes to the refined grain, things like white rice, you’ve removed the bulk of that naturally occurring nutrition in that grain,” she said. “You’ve removed the hull, that nutrient-rich germ layer, and you’re just kind of left with the starch.”

Creating a game plan

My plan was to cook a new, different meal every night, then take the leftovers to work for lunch.

With my printed copy of the report and Willett’s guidelines in mind, I assembled a collection of plant-based recipes and meticulously meal planned—an activity I find mundane and usually avoid.  I more often grocery shop with some loose meal ideas in mind while buying whatever looks good to me. Better yet—I buy something in season at a farmer’s market and cobble together a meal from there.

But because I was making a week’s worth of meals with fresh veggies, I needed to make sure none of my produce was wasted. Mushrooms, for instance, get rubbery after a day or two in the fridge, so I decided I would cook those on the first day of the experiment. Carrots, on the other hand, keep relatively well, so I decided to cook those at the end of week. 

Then while at the grocery store I made several swaps that adhered more closely with the planetary health diet. I exchanged white rice for brown rice, regular pasta noodles for a whole grain variety, ground meat for tofu, and my favorite full-fat cream-on-top yogurt for no-sugar-added dairy-free yogurt.

I also wanted to have a healthier afternoon snack than my usual salty, crunchy go-to, but lacking a more creative idea, I just bought seven honeycrisp apples.

How it went

What I found easy

The first meal of the day was the easiest for me to adapt to the report’s dietary guidelines. I generally make my breakfast at home—either yogurt or oatmeal piled high with various seeds, nuts, and berries—and eat it at my desk at National Geographic’s headquarters in Washington, D.C. Because the diet only allows for one serving of dairy per day, I simply switched to dairy-free yogurt in the morning when I knew I might have dairy in the evening.

What I struggled with

The week I tried this diet, I was slammed with a big Earth Day project at work. I was at the office later than usual, generally leaving after 7 p.m.

With this schedule, I realized it was a little too ambitious to cook a new dinner every night. Some of the meals I had planned on Saturday were dishes I was cooking for the first time. By the time I got home, following a new recipe felt like a chore. I pivoted to a few solutions that ultimately helped me stick to the diet:

• Larger batches: On Monday night, I spent just under two hours peeling, chopping, steaming, roasting, and stirring my way to a veritable fiber platter made of brown rice, veggies (squash, kale, seaweed), tofu, and white beans with a tahini-based sauce. I ended up with so much food that this became my lunch from Tuesday through Friday. I also made a large batch of kale pesto on Tuesday that I reheated for dinner on Thursday.
• Simpler foods: On Wednesday, I really didn’t want to cook the dish I had planned for that day, so instead I used a fork to stab some steam holes into two sweet potatoes (one for me, one to top off my dog’s kibble) and popped them in a 400-degree oven until it was mushy inside. With a drizzle of olive oil and sprinkle of salt and red pepper flakes, it wasn’t the most exciting dinner, but it was decently nutritious and satiating.

What surprised me

I love a carbohydrate—a refined carbohydrate. When I imagined the taste of whole grains like brown rice and whole grain bread the diet called for, I imagined something as exciting as cardboard.

I was genuinely surprised by how good these grains could taste. Farro cooked in chicken stock had a nice nutty flavor to it, whole grain pasta slathered in kale pesto sauce didn’t taste any different from the more commonly sold refined pasta, and I happened to love the multigrain bread sold at the bakery near my house.

Why I’ll stick to the diet

At the onset of this experiment, I suspected I might feel healthier, and my suspicion was right. Eating this way was by no means a total physical transformation, but I had a lighter step and a bit more energy.

The real health benefits from switching to this diet accrue over time. After feeling moderately better in just a week, I wondered how I might feel after eating this way for a year, or for a lifetime.

I think that’s likely the most persuasive benefit of this diet, if you’re looking for one. The dotted line between your cheeseburger habit and climate change is a lot longer than the dotted line between how much red, processed meat you eat and your long-term heart health. Come for the health benefits, stay for the planetary ones.

I plan to continue eating more of the plant-based meals and whole grains I tried during this experiment. I’ll be keeping one crucial tip from Fetter in mind though: “Leave room for occasional indulgences. It's good for our mental health to enjoy an occasional treat.”