How to eat 30 plants a week without thinking about it

Where the number came from

The American Gut Project, published by McDonald and colleagues in mSystems in 2018, looked at thousands of people and found that those eating more than 30 different plant types a week had noticeably more diverse gut bacteria than those eating 10 or fewer. It was the variety that tracked with the difference, not the volume and not whether someone called themselves vegan.

Diversity matters because a varied gut community is a stable one. Different bacteria feed on different fibres, so a narrow diet feeds a narrow set of them. This is observational work rather than a controlled trial, so it shows a pattern rather than proving cause, but the pattern is consistent and the advice it points at is harmless. Eat more different plants.

Ten ways to get there

Salad greens

Mixing three or four greens instead of buying one bag is three or four plants instead of one, for the same money and no extra effort. Spinach for iron, arugula for pepper, romaine for crunch.

Smoothies

The cheapest place to stack plants, because nobody tastes the spinach. A banana, a handful of greens, frozen berries and a spoonful of seeds is five before breakfast.

Snack on raw vegetables

Carrots, celery, cucumber and cherry tomatoes cut at the start of the week get eaten. The same vegetables whole in the drawer do not.

Nuts and seeds

Each one is its own plant. A jar of mixed almonds, walnuts, pumpkin and sunflower seeds on the counter is four, sprinkled over anything.

Fruit

Frozen berry mixes are the efficient version, since a bag of three berries is three plants and it does not go off before you get to it.

Mushrooms

Not technically plants, botanically speaking, and nobody counting is going to mind. Cremini, shiitake and oyster all taste different and all behave differently in a pan. Sautéed with garlic and thyme they will carry a whole side dish.

Fermented foods

Sauerkraut, kimchi and plant-based kefir bring live bacteria in on top of the plants themselves. A forkful of sauerkraut improves almost any savoury plate, which is a claim we will defend.

Fresh herbs

The most overlooked entry on this list. Basil, cilantro, parsley, dill and mint each count, they are cheap, and a handful of any of them changes a dish more than an extra vegetable would.

Whole grains

Quinoa, brown rice, farro, barley and oats are five distinct plants. Rotating which grain goes under dinner is one decision a week for four extra entries.

Legumes

Black beans, chickpeas, lentils, white beans and split peas, each its own plant, each bringing protein and a large amount of fibre. A chili with two kinds of bean counts twice.