The Science Behind the '30 Plants a Week' Goal
For years, nutritional advice focused on getting a minimum number of daily fruit and vegetable portions. However, research now highlights that the diversity of plant intake is a crucial factor for a healthy gut microbiome. The American Gut Project, a large-scale citizen science study, found that individuals who ate 30 or more different types of plants per week had a significantly more diverse and resilient gut microbiome compared to those eating 10 or fewer.
A diverse gut microbiome is crucial for overall health, as it is linked to better immune function, digestion, and metabolic health. Different plants contain unique compounds, including fibre and polyphenols, that feed different strains of beneficial gut bacteria. Therefore, eating a wide variety of plants ensures that you nourish a broader range of microorganisms in your gut.
It's important to remember that this challenge is about variety, not portion size. A small amount of a new plant food is all it takes to earn a "plant point" for the week. However, a specific item only counts once per seven-day period. For example, eating an apple on Monday and then again on Tuesday still only counts as one plant for that week.
The Six Plant Food Categories that Count
To help you track your intake, plant-based foods can be broken down into six main categories:
1. Fruits
All fruits, whether fresh, frozen, canned, or dried, contribute to your weekly tally. Different colours of the same fruit also count separately because they contain different phytonutrients. For instance, a red apple and a green apple are two distinct points. Don't forget fruits that are often mistaken for vegetables, such as tomatoes, avocados, and olives.
2. Vegetables
This is a broad category, and variety is your friend. Include leafy greens, root vegetables, alliums (like onions and garlic), and mushrooms. Fermented vegetables, such as sauerkraut and kimchi, also count and provide beneficial probiotics. Like fruits, different coloured vegetables offer different nutrients and count separately. Red, yellow, and green bell peppers, for example, would give you three separate points.
3. Legumes
Legumes, including beans, lentils, chickpeas, and peas, are an excellent source of fibre and plant protein. Using a mixed bean salad or a soup mix containing various beans can be an easy way to increase your diversity.
4. Wholegrains
Focus on whole grain options, as they contain the entire grain kernel, including the fibrous bran and germ. Examples include brown rice, oats, barley, quinoa, spelt, and wholewheat pasta. Highly processed grains, like white rice, white pasta, and white bread, do not count, as they have been stripped of many beneficial fibres and nutrients.
5. Nuts and Seeds
Almonds, walnuts, chia seeds, flaxseeds, pumpkin seeds, and sesame seeds all contribute points. A bag of mixed nuts or seeds is a quick and effective way to gain multiple points in one go. Nut butters and tahini also count.
6. Herbs and Spices
Often overlooked, herbs and spices are a simple way to add variety. They are concentrated sources of polyphenols, beneficial plant compounds with antioxidant and anti-inflammatory properties. Since you typically consume them in small quantities, they are often counted as a fraction of a point, such as a quarter point each.
Unexpected Plant Food Contributions
Some pantry staples also contain beneficial plant compounds and count towards your goal. These include:
- Coffee: Freshly ground, instant, or decaf coffee.
- Tea: Black or green tea.
- Dark Chocolate: With 70% or more cocoa solids.
- Extra Virgin Olive Oil: A staple of the gut-healthy Mediterranean diet.
- Tofu and other soy products.
Comparison Table: Standard Diet vs. 30 Plants a Week Diet
| Meal | Standard Diet Example | 30 Plants a Week Diet Example | Point Difference |
|---|---|---|---|
| Breakfast | Slice of white toast with margarine (0 plants) | Oatmeal with mixed berries, chia seeds, cinnamon, and a handful of mixed nuts (5+ plants) | Substantial |
| Lunch | Ham and cheese sandwich on white bread (0 plants) | Mixed bean salad with cucumber, cherry tomatoes, and red onion, topped with pumpkin seeds and a sprinkle of paprika (6+ plants) | Significant |
| Dinner | Plain pasta with a single-ingredient tomato sauce (1 plant) | Wholewheat pasta with a sauce containing tinned tomatoes, courgette, spinach, mushrooms, and herbs like basil and oregano (6+ plants) | High |
| Snack | A single apple (1 plant) | A handful of mixed trail mix (almonds, raisins, sunflower seeds, cashews) and carrot sticks with hummus (6+ plants) | Moderate to High |
How to Build Towards 30 a Week
Aiming for 30 different plants can seem daunting at first, but with a few simple strategies, it's very achievable. The key is to think about adding diversity to meals you already eat:
- Supercharge your snacks: Swap a single fruit for a mix of different berries or a handful of mixed nuts and seeds.
- Embrace the smoothie: A single smoothie can easily contain several plants, including leafy greens, mixed fruits, seeds, and even herbs like mint.
- Rethink your rice and pasta: Alternate between different wholegrains like brown rice, quinoa, and barley throughout the week. Consider lentil or pea-based pastas.
- Add herbs and spices liberally: Use fresh herbs in salads and dried spices in curries, soups, and marinades. Remember, each different one counts.
- Go for mixed products: Buy bags of mixed frozen vegetables, pre-packaged salad mixes, or canned mixed beans to maximize variety with minimal effort.
- Use your freezer: Stock up on different frozen fruits and vegetables. They are often cheaper, last longer, and are just as nutritious as fresh produce.
Conclusion: A Diverse Diet for a Healthier You
Eating 30 different plants a week is a straightforward, evidence-backed strategy for boosting gut microbiome diversity and promoting overall health. It shifts the focus from simply counting portions to celebrating variety across all plant-based food groups, including fruits, vegetables, whole grains, legumes, nuts, seeds, herbs, and spices. While the number 30 is a helpful target, remember that any increase in plant diversity is a step in the right direction. By making small, mindful changes and experimenting with new ingredients, you can build healthier eating habits that benefit your gut and body in the long run. For more information on the science behind gut health, consult resources from organisations like the American Gut Project.
