Why do experts recommend eating 30 plants a week?
The advice to eat 30 plants a week is based on the project’s study of thousands of people – or, more specifically, their poop. It found those who ate a wider variety of plant foods – fruits and vegetables, but also seeds, nuts, whole grains and spices – had a more diverse gut microbiome.
A wider variety of gut bacteria provides a basis for better overall health and wellbeing: greater resilience to withstand pathogens, better digestion and better brain function. Since the project published its message, other experts have joined the call for 30 plants a week; Catherine Rabess, a dietitian and NHS clinical lead, released her book, The 30 Plan, this February, while Dr Megan Rossi, author of How to Eat More Plants and Love Your Gut, claims eating a diverse range of plants is her only dietary rule.Spector’s 30-a-week approach is explained in detail on the website of his company, Zoe, a biotech firm aimed at helping people better understand their personal nutrition needs, best known for its continuous glucose monitors. There, eating 30 plants a week is conveyed as a personal “challenge” – a self-test anyone can do at home by tracking the plants you eat.
How does the 30 plants challenge work?
Here’s how it works: every individual plant you eat counts as one “plant point”, even if you only eat a small amount of that plant, like a couple of carrot sticks or one strawberry. Herbs, spices and garlic also count, but only for quarter of a point. Meanwhile, different colored versions of plants, like red and yellow bell peppers, count separately as a point each, since different colored plants contain slightly different amounts of vitamins, minerals and phytonutrients. But some items don’t count at all – like white rice and potatoes (they spike your blood sugar too much, according to Spector, and contain less fiber and nutrients than other plants).
Relatively simple processed foods like popcorn count, but if the food has more than a handful of recognizable ingredients, it probably doesn’t count; nor do any juices. The idea is to start with bolstering diversity, and worry about quantity later.According to Joan Frank, assistant program director at the University of California, Davis department of nutrition, the idea of eating 30 plants a week is nutritionally unimpeachable and excellent for health unless you have gastrointestinal (GI) problems that may make fiber hard to digest, in which case, proceed with caution. However, “some people don’t have access to a variety of different plants. We would hate for people to think, ‘I can’t do this because I can’t afford it,’” she says. “You certainly get benefits from eating as many plants as you can,” she says, even if you can’t get 30 different ones every week.