How to Eat 30 Plants a Week — And Why We Challenge You to Go Further

You've probably heard the recommendation: eat 30 different plants a week. It's been championed by Professor Tim Spector, featured in his books Food for Life and Spoon-Fed, and popularised by the ZOE nutrition programme. But what does it actually mean in practice — and is there a reason to aim even higher?

To put it in context: research into hunter-gatherer communities such as the Hadza of Tanzania suggests our ancestors regularly ate several hundred different whole foods over the course of a year. Most people in Western countries today rotate through roughly the same 20–30 foods week after week. The 30 plants recommendation is a practical modern target — but it's worth remembering it's still a fraction of the diversity we evolved eating.

Where does the 30 plants idea come from?

The recommendation emerged from one of the largest studies of gut health ever conducted. The American Gut Project collected data from thousands of participants across multiple countries, analysing the relationship between diet and the diversity of bacteria living in the gut.

The finding was striking:

The type of diet mattered less than its diversity. People who ate 30 or more different plant foods a week consistently had richer, more diverse gut microbiomes — and a diverse microbiome is one of the strongest indicators of overall gut health.

What counts as a "plant"?

This is where many people underestimate how achievable 30 plants actually is. A "plant" in this context means any whole plant food — and that category is broader than most people think:

• Fruits — apple, banana, blueberries, mango, avocado
• Vegetables — broccoli, carrot, spinach, capsicum, courgette
• Whole grains — oats, brown rice, rye bread, quinoa, barley
• Legumes — lentils, chickpeas, black beans, edamame, peas
• Nuts — almonds, walnuts, cashews, pecans, brazil nuts
• Seeds — chia seeds, flaxseeds, sunflower seeds, pumpkin seeds
• Herbs — basil, parsley, coriander, thyme, rosemary
• Spices — turmeric, cumin, cinnamon, paprika, ginger

That last two categories surprise a lot of people. Herbs and spices count — and they're often the easiest way to boost your weekly total. A single curry can add four or five plants before you've even thought about the vegetables.

A realistic week that hits 30 plants

Notice how Wednesday's dinner alone contributed seven plants. Cooking from scratch with whole ingredients is the single biggest lever for increasing plant diversity.

What about going beyond 30?

It's worth being honest here: Tim Spector's research specifically identified 30 plants as the threshold where microbiome benefits become clear. There's no peer-reviewed study that compared 30 with 40 and declared 40 the winner. So the 40 Foods Challenge isn't claiming the science says 40 is better.

What it does claim is this: aiming higher makes you more likely to consistently clear the threshold that the science does support. If you're targeting 30 and have a busy week, you might land on 22. If you're targeting 40, a difficult week still leaves you well above 30.

The challenge also counts all whole foods, not just plants. Dr Michael Greger's Daily Dozen framework, NHS doctor Dr Rupy Aujla, and researchers like Valter Longo all point to the same broader principle: diverse, whole, minimally processed foods across as many categories as possible. Fermented foods introduce live microbial cultures. Minimally processed animal products provide B12, omega-3s, and complete proteins that are hard to get from plants alone.

The case for 40 whole foods

The 40 Foods Challenge builds on the 30 plants foundation and extends it across your whole diet:

Think of 30 plants as the science-backed baseline. The 40 Foods Challenge is the stretch goal that gets you well above it — and keeps the habit interesting week after week.

Tips to increase your weekly plant count

• Count every herb and spice separately — a tagine with cumin, coriander, cinnamon, and ginger is already 4 plants
• Buy mixed bags — mixed nuts, mixed seeds, mixed salad leaves, mixed berries all add multiple plants at once
• Rotate your grains — oats on Monday, rye on Tuesday, brown rice on Wednesday
• Try one new food a week — just one unfamiliar ingredient keeps your total growing
• Eat seasonally — seasonal produce naturally rotates variety through the year
• Cook legumes into everything — lentils, chickpeas, and beans are easy to add to soups, salads, and curries