The Eat-the-Rainbow Diversity Rule
Build plant variety by deliberately rotating colours and food groups
- Difficulty
- Easy
- Time to result
- ~ongoing to results
- Steps
- 4
- Confidence
- 86%
Mills uses colour as a simple planning proxy for plant diversity. He argues that differently coloured foods contain different plant compounds and fibres, many of which interact with the gut microbiome. Rather than trying to identify the single food a person needs, the rule expands the range across a week: reds and purples, greens, orange roots, grains, beans, lentils, herbs, and spices. He cites a target used by some advocates of roughly 30 different plants per week, but presents diversity—not an exact threshold—as the main idea. The framework also addresses cost by favouring inexpensive staples and home-cooked meals. It is a meal-planning heuristic, not a guarantee of disease prevention or a substitute for personalised dietary advice.
Origin
Extracted from The Diary of a CEO
Core principles
- 01Colour is a practical proxy for plant variety
- 02Different plants provide different fibres and compounds
- 03Diversity matters more than finding one perfect food
- 04Affordable staples can supply variety
How to run it
- 1
Audit the current range
List the distinct plants eaten in a typical week, including herbs, spices, grains, beans, and vegetables.
Pro tip Count varieties, not repeated servings of the same plant.
Watch out Do not add foods that conflict with known allergies or medical restrictions.
- 2
Find the colour gaps
Look for absent or underrepresented colour groups, especially reds, purples, greens, and orange roots.
Pro tip A shopping list grouped by colour makes gaps obvious.
- 3
Diversify the foundations
Rotate roots, leafy or cruciferous vegetables, whole grains, beans, peas, and lentils rather than relying only on colourful fruit.
Pro tip Use low-cost pulses and frozen vegetables to widen the range.
Watch out Increase fibre gradually if a rapid change causes digestive discomfort.
- 4
Review weekly
Check whether the range expanded and choose a few different plants for the next week. Treat the count as a prompt, not a pass-fail medical target.
Pro tip Rotate varieties across weeks to avoid making the plan repetitive.
In the wild
A home cook combines lentils, a root vegetable, broccoli, tomato, and several spices in one meal. Across the rest of the week, they rotate beans, grains, greens, berries, and purple vegetables rather than buying expensive supplements or relying on one supposed superfood.
→ The weekly menu contains a broader range of plant foods while using inexpensive staples.
Common mistakes
Treating colour as proof
Colour is a planning shortcut, not evidence that a specific meal will prevent or treat disease.
Chasing an exact count
The transcript cites 30 plants as current advice from some people, not a universal requirement. Use it as a diversity prompt.
Is it for you?
Best for
It is best for generally healthy adults planning a varied plant-rich diet within their needs.
Not ideal for
It is not a personalised diet for allergies, gastrointestinal disease, kidney disease, or other medical restrictions.
From the transcript
“Eat your rainbow. The more different colors, the better.”
“the best thing to do is to have as much diversity as possible”
From the episode
No.1 Herbal Medicine Expert: This Over The Counter Drug Is Quietly Killing You & They’re Lying About Medicinal Plants!