Thirty different plant foods a week is the number people cite, and it comes from a single 2018 study rather than from any official guideline. There is nothing magic about 30. What the research supports is the direction: the more different plants you eat across a week, the more diverse your gut bacteria tend to be, and diversity is currently the closest thing we have to a marker of a healthy gut community.
Most people are surprised by two things. The first is how far they are from 30. The second is how quickly the count moves once you know what counts.
The question got a fresh look in Alice Callahan's September 29, 2026 New York Times piece asking whether you really need 30 plants a week. The experts she interviewed landed where the evidence does: plant variety is worth pursuing, but 30 is not a proven threshold, and getting enough fiber from whole plants matters more than hitting an exact count. Below is what each study actually found, from weakest evidence to strongest.
Where the 30 plants number came from
McDonald and colleagues published results from the American Gut Project in the journal mSystems in 2018. The American Gut Project is a large citizen-science effort, with thousands of participants sending in stool samples along with dietary questionnaires. The 30-plant comparison itself, though, drew on a small subset: 85 people, roughly half of whom said they ate more than 30 different plants a week and half fewer than 10. The 30-plus group had more diverse gut bacterial communities.
Four caveats matter, and skipping them is how a study becomes a slogan.
- It is small. The headline comparison rests on 85 people, not on the full cohort.
- It is observational. People eating 30 plants a week differ from people eating 10 in many ways beyond plants, and the study cannot separate those.
- Diet was self-reported, which is the weakest link in most nutrition research.
- Thirty was a comparison point in the analysis, not a threshold anyone identified as optimal. Twenty-five is not a failure and 35 is not twice as good.
What makes the finding worth acting on anyway is that it points the same direction as better-established evidence. Different plants carry different fiber types and different polyphenols, and different gut bacteria feed on different ones. Eating the same three vegetables all week feeds a narrower set of microbes than eating twelve. The Dietary Guidelines for Americans, 2025-2030 make the same point in their own words, naming vegetables, fruits, fermented foods and other high-fiber foods as what supports a diverse microbiome.
What newer studies show about 30 plants a week
Three newer pieces of evidence have tested the idea more directly. None of them shows that 30 is a magic number.
| Study | Design | Who | What it found |
|---|---|---|---|
| McDonald et al., 2018 (American Gut) | Observational, self-reported diet | 85 adults compared: about half eating 30+ plants a week, half fewer than 10 | The 30+ group had more diverse gut bacteria. Association only |
| Larger analysis by Rob Knight and colleagues | Observational. Not peer-reviewed or published, as reported by The New York Times | More than 3,000 adults | Eating 11 to 20 plants a week was associated with similar gut diversity to eating 30 or more |
| Stanford et al., 2025 | Randomized crossover trial, 6 weeks per diet | 25 adults in Australia with stage 3 to 4 chronic kidney disease | 30+ plants a week, compared with 15 or fewer, reduced symptom burden including constipation and shifted gut bacteria toward producing butyrate. The low-variety diet reduced microbial diversity. The main outcome, kidney-related toxins, did not consistently fall |
| Creedon et al., 2026 (ZOE BIOME trial). The blend is called Daily30+ in the paper; ZOE sells it today as Daily30 and notes the recipe has since changed slightly | Randomized controlled trial, 6 weeks | 399 adults with fiber intake under 20 g a day, 349 analyzed | A daily 30 g serving (two scoops) of the trial blend, a mix of 30+ plants made for ZOE, changed the relative abundance of more gut species than a crouton control (57 vs 14) or a probiotic (57 vs 4). Participants reported less constipation, indigestion, heartburn and flatulence and more energy than the control group. Shannon diversity did not differ from control, and species richness fell slightly relative to control, which the authors note may not reliably reflect gut health |
Two caveats apply to both trials. In each, eating more plant variety also meant eating more fiber, so, as experts quoted by The New York Times noted, these trials cannot separate whether the variety, the extra fiber or both drove the results. And the 2026 trial was funded by ZOE Ltd, which sells the blend, and most of its authors are ZOE co-founders, consultants, or current or former employees, as the paper discloses.
The fair summary: more plant variety is associated with a more diverse gut, and in trials it has eased constipation, but nobody has shown that 30 beats 20. For the probiotic side of that question, see probiotics or fiber: which one actually changes your gut.
What counts as a plant
This is the part that changes the math. It is not 30 vegetables. It is 30 distinct plant species across every category.
| Category | Examples | How it counts |
|---|---|---|
| Vegetables | Spinach, kale, carrot, broccoli, onion, pepper | 1 each |
| Fruit | Apple, blueberry, lemon, banana | 1 each |
| Whole grains | Oats, brown rice, quinoa, buckwheat | 1 each |
| Legumes | Black beans, chickpeas, lentils, peanuts | 1 each |
| Nuts and seeds | Almonds, walnuts, pumpkin seeds, chia | 1 each |
| Herbs and spices | Basil, cumin, cinnamon, black pepper | Commonly counted as 1/4 each, since portions are tiny |
Two rules keep the count honest. Different varieties of the same species count once, so a red apple and a green apple are one plant, and red, white, and yellow onions are one plant. Coffee, tea, olive oil, and dark chocolate are plant-derived and are commonly counted, though they contribute polyphenols rather than meaningful fiber.
What 30 in a week actually looks like
Nobody hits 30 by trying to eat 30 things. It happens by making four or five choices that each carry several plants.
| One choice | Plants it adds | Running total |
|---|---|---|
| Oatmeal with berries, walnuts, and cinnamon | Oats, blueberry, raspberry, walnut, cinnamon | 5 |
| A bag of mixed frozen vegetables | Pea, corn, carrot, green bean | 9 |
| A three-bean chili with onion, garlic, tomato, cumin, chili | Black bean, kidney bean, pinto bean, onion, garlic, tomato, cumin, chili | 17 |
| A salad with mixed greens, cucumber, pepper, chickpeas, pumpkin seeds | Spinach, arugula, cucumber, pepper, chickpea, pumpkin seed | 23 |
| Trail mix and a piece of fruit | Almond, cashew, raisin, apple | 27 |
| Stir fry with broccoli, mushroom, ginger, brown rice | Broccoli, mushroom, ginger, brown rice | 31 |
Mixed products do disproportionate work. A frozen vegetable medley, a multi-bean chili, a seed-heavy trail mix, and a mixed-greens bag each move the count several points for one decision. Buying variety once beats remembering variety daily.
Diversity is not a substitute for quantity
Counting plants is a useful game, but it can distract from the more basic problem. Roughly 90 percent of Americans fall short of the recommended daily vegetable intake, which the Dietary Guidelines for Americans, 2025-2030 set at 3 servings a day at 2,000 calories, where a serving is 1 cup raw or cooked or 2 cups leafy greens. Average fiber intake sits near 16 g a day against a recommendation of about 14 g per 1,000 calories, which works out to roughly 21 to 38 g a day depending on age and sex. That fiber target, met from a variety of plant foods, is the goal researchers interviewed by The New York Times point to as better supported than a plant count. For how to get there, see how much fiber you need a day.
A large series of systematic reviews and meta-analyses published in The Lancet in 2019 by Reynolds and colleagues found the clearest health benefits at fiber intakes of 25 to 29 g a day, with evidence suggesting more may be better. Thirty different plants in trace amounts does not get you there. Thirty plants in real portions does.
Where SaladPower fits
One 8 oz pouch is six distinct plants: spinach, kale, carrot, broccoli, apple, and lemon. That is 6 of your 30 in one decision, with 5 g of fiber, about 90 calories, and no added sugar. Each pouch delivers 2x the USDA daily recommended vegetable intake. Because it is commercially processed, sealed, and shelf-stable, the variety does not depend on anything surviving in a crisper drawer.
It is a contribution, not a strategy. A week built on a pouch and nothing else is a narrow week. The point of plant diversity is breadth, and we would rather you get there with beans and seeds and herbs too. What a pouch reliably does is keep six plants in the count on the days when cooking does not happen.
Frequently asked questions
Do I really need 30 plants a week?
No official guideline says 30. The number comes from a 2018 American Gut Project comparison of 85 people, in which those eating more than 30 different plant types per week had more diverse gut bacteria than those eating fewer than 10. A larger, not yet published analysis of more than 3,000 adults found 11 to 20 plants a week was associated with similar diversity. Treat 30 as a direction rather than a target.
Do herbs and spices count toward 30 plants?
Yes, and they are commonly counted as a quarter of a plant each because the portions are so small. A teaspoon of cumin does not contribute the fiber that a half cup of lentils does, but dried herbs and spices are among the most polyphenol-dense foods by weight.
Do different colors of the same vegetable count separately?
No. Varieties of the same species count once. Red, white, and yellow onions are one plant. Green and red apples are one plant. Different species in the same family do count separately, so broccoli, cauliflower, and kale each count.
Does coffee count as a plant?
It is commonly counted, along with tea, olive oil, and dark chocolate, because they are plant-derived and carry polyphenols. They contribute almost no fiber, so counting them can inflate the number without changing much. Whole plants are what move fiber intake.
Is plant variety more important than eating more vegetables?
Quantity comes first. About 90 percent of Americans fall short of the recommended vegetable intake, and average fiber intake is roughly 16 g a day against a 21 to 38 g recommendation. Variety is a refinement on top of adequate intake, not a replacement for it.
Do 30-plant supplements work?
One randomized trial has tested one. In the 2026 BIOME trial of 399 adults, an earlier formulation of ZOE's Daily30 blend, taken at two scoops a day, shifted the relative abundance of more gut species than a crouton control, and participants reported less constipation and more energy. Overall gut diversity did not increase. The trial was funded by ZOE, which sells the blend. Whole plant foods remain the better-supported way to add variety and fiber.
Sources
- McDonald D, Hyde E, Debelius JW, et al. "American Gut: an Open Platform for Citizen Science Microbiome Research." mSystems. 2018;3(3):e00031-18. doi.org/10.1128/mSystems.00031-18
- Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. "Carbohydrate quality and human health: a series of systematic reviews and meta-analyses." The Lancet. 2019;393(10170):434-445. doi.org/10.1016/S0140-6736(18)31809-9
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2025-2030. realfood.gov
- Callahan A. "Do I Really Need to Eat 30 Different Plants Each Week?" The New York Times. September 29, 2026. Read the original article
- Stanford J, Stefoska-Needham A, Jiang X, et al. "High-Diversity Plant-Based Diet and Gut Microbiome, Plasma Metabolome, and Symptoms in Adults with CKD." Clinical Journal of the American Society of Nephrology. 2025;20(5):619-631. doi.org/10.2215/CJN.0000000682
- Creedon AC, Bernard HM, Amati F, et al. "Does a diverse whole-food plant-based dietary intervention improve gut microbiome composition, gut symptoms, energy and hunger in healthy adults? A randomised controlled trial." British Journal of Nutrition. Published online July 9, 2026:1-19. doi.org/10.1017/S0007114526107703
- ZOE. Daily30 product page. zoe.com/en-us/daily30
- SaladPower Nutrition Facts panel, per 8 oz pouch.
All claims about ZOE and its Daily30 blend (tested as Daily30+) on this page come from ZOE's published trial (Creedon et al., British Journal of Nutrition, 2026) and from ZOE's Daily30 page on zoe.com, as of October 5, 2026.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
