Eating better doesn’t just mean choosing fruit and vegetables more often. It may also be important to vary what we bring to the table as much as possible. From this idea was born the so-called “30 plants a week challenge”, a food trend that invites you to consume at least 30 different foods of plant origin over seven days.
It might seem like just a trend born on social media, but behind this number there is actually important scientific research on the intestinal microbiota.
What is the 30 plant challenge
The rule is very simple: within a week you should try to eat 30 different types of plant foods. It doesn’t mean eating 30 servings of vegetables or even consuming huge amounts of food. The goal is to increase the variety of the diet.
The count may include fruit and vegetables, but also legumes, whole grains, dried fruit, seeds, aromatic herbs and spices. In practice, a handful of nuts can add an entry, as can a portion of chickpeas, a salad with arugula, a plate of oats or a fruit different from the one eaten the previous day.
The idea has become particularly popular because it turns food variety into a kind of game: instead of counting calories or eliminating foods, you simply try to add new plants to your week.
From microbiota research to social media
The origin of the famous number 30 can be traced back to‘American Gut Projectone of the largest research projects on the human microbiome, the results of which were published in 2018 in the scientific journal mSystems.
The researchers analyzed the samples and eating habits of over 10,000 participants, also observing the relationship between the variety of plant foods consumed and the composition of the intestinal microbiota. People who reported eating more than 30 different types of plants per week had greater microbial diversity than those who consumed 10 or fewer.
From that moment on, the concept of “30 plants a week” moved out of the realm of research and became a real food goal worth trying.
The diffusion on social media is well documented. In 2025, for example, ProVeg International told how, after the release of the Netflix documentary “Hack Your Health: The Secrets of Your Gut“, the theme of 30 plants had started to appear more and more often on Instagram, to the point of pushing the author to try the challenge personally.
The trend has also arrived in the world of food and catering: in 2025 FoodNavigator described “30 plants a week” as a growing trend, also supported by British food popularisation figures.
And the phenomenon does not seem to have ended, in 2026 the challenge continues to be proposed through trackers, recipes and initiatives dedicated to plant-based proposals.
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Why variety could be important for the microbiota
Our intestines are home to a huge community of microorganisms that continually interact with what we eat. In fact, the different plants provide fibers, polyphenols and other substances that can be used by intestinal microorganisms. Increasing the variety of plant sources therefore means making a wider range of nutrients and compounds available to the microbiota.
The Microsetta Initiative of the University of California San Diego, which takes up the legacy of the American Gut Project, explains that in their dataset, people who reported consuming at least 30 different types of plants per week had a greater diversity of microbiota compared to those who consumed fewer.
But be careful: greater diversity of the microbiota does not automatically mean greater health, and above all it does not mean that there is a threshold beyond which our intestine suddenly becomes “healthy”.
In short, the number 30 is not a magic threshold. This is precisely the point which is worth clarifying.
The 2018 study found an association between variety of plants consumed and characteristics of the microbiota. It has not been proven that eating exactly 30 plants a week improves your health, nor that 30 is the minimum number needed for a healthy gut.
Even the Guardian, in an in-depth analysis published in July 2026, brought the famous threshold back under the microscope: according to the experts cited in the article, the number 30 is rather arbitrary. In fact, the research did not systematically compare 10, 20, 30 and 35 plants to identify a precise turning point.
Then there is another important limitation: it is an observational research. People who eat a wide variety of vegetables may also have other habits associated with better health, from physical activity to sleep to overall consumption of less ultra-processed foods. For this reason we cannot say that it was the simple fact of exceeding 30 that determined the differences observed.
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So is it worth a try?
Yes, but without turning the number into a new food obsession. The most interesting message of the challenge is not so much “you have to reach 30”, but rather “try to eat more variety”.
If during the week we always eat the same vegetables, the same fruit and the same cereals, we can simply try to change something. Chickpeas instead of beans, oats instead of the usual cereal, a handful of nuts, pumpkin seeds, a different seasonal vegetable, a few more aromatic herbs.
Even without reaching 30, gradually increasing variety can be a simple way to improve the overall quality of your diet.
What can we count in the 30 plants?
You don’t have to think about 30 huge plates of salad. The list can grow much easier than it seems:
You don’t even need to revolutionize your diet overnight. A breakfast with oats, seeds and berries, a salad enriched with legumes and seeds for lunch and a dinner with different vegetables can already significantly increase the number of plants consumed over the course of the week.
Sources: American Gut Project / Microsetta Initiative – University of California San Diego
