30 plants a week: what counts, why it matters, and how to get there

“Eat more vegetables” is advice everyone has heard and few people find motivating. “Eat 30 different plants a week” turns out to be a lot more fun — it's a game you can actually win, and it nudges you towards variety rather than restriction.

Where the number 30 comes from

The idea comes from the American Gut Project, a large citizen-science study of the gut microbiome. Participants who ate more than 30 different types of plants a week had a more diverse gut microbiome than those who ate 10 or fewer. A diverse microbiome is generally considered a marker of a healthier gut.

It's an observational finding, not a magic threshold — 28 isn't a failure and 35 isn't a cure. But as a simple, positive target, 30 works remarkably well: it rewards adding things rather than cutting them out.

What counts as a plant

More than most people expect. Each different plant counts once per week:

• Vegetables — fresh, frozen or canned. Tomato, spinach, carrot, onion, peppers.
• Fruit — apples, berries, bananas, citrus, dried fruit.
• Whole grains — oats, buckwheat, brown rice, barley, quinoa, whole-wheat bread.
• Legumes — lentils, chickpeas, beans, peas, edamame, tofu.
• Nuts and seeds — walnuts, almonds, sunflower, pumpkin, chia, sesame.
• Herbs and spices — basil, parsley, cumin, cinnamon. Because you usually eat a pinch rather than a portion, they're commonly counted as a quarter each.

What doesn't count: juice (the fiber is gone), and heavily refined products where little of the original plant is left.

Why variety beats “more of the same”

Different plants carry different fibers and plant compounds, and different gut bacteria specialize in breaking them down. A kilo of apples a week is great; apples, pears, lentils, oats and walnuts feed a much wider crowd. That's the whole logic behind counting types instead of portions.

Easy ways to get to 30

1. Buy mixes. A bag of frozen stir-fry vegetables, mixed beans or a seed mix can be five plants in one spoonful.
2. Top everything. A handful of nuts or seeds on porridge, yogurt or salad adds two or three plants with zero effort.
3. Rotate your staples. Swap rice for buckwheat or barley one day, change the fruit in your breakfast every few days.
4. Cook soups and stews. They happily take whatever is in the fridge — onion, carrot, celery, lentils, tomatoes, herbs.
5. Use herbs and spices generously. Four of them make a whole plant point — and a better dinner.

A typical day like oats with berries and walnuts, a lentil soup, and a stir-fry with rice and three vegetables is already about ten different plants.

How to count without a spreadsheet

Counting by hand gets old fast — nobody wants to remember whether there was parsley in Tuesday's soup. In foodoo you just log meals as usual, with a photo or a sentence. foodoo recognizes the plants in each dish and keeps a weekly count out of 30, with herbs and spices as quarters. Tap the card and you'll see every plant you've had this week — which also makes it obvious what to try next.

Next to it you'll see how processed your food was and where your fiber, iron or protein came from. And if you'd rather not see calories at all, switch on “No numbers” mode — plants and processing stay, the numbers go.