You’ve heard it from dietitians, pediatricians, and probably a grandmother: eat the rainbow. It sounds like a slogan, but it’s one of the few pieces of nutrition advice that almost everyone in the field agrees on. The colors in plant foods come from different natural compounds, so eating across the colors is a shortcut to eating across the nutrients.
We built Crunchi on the belief that food is medicine: every meal is information your body acts on, and the colors are part of the message. The catch is that nobody tells you how to keep track. Crunchi makes it effortless: your meals literally fill a rainbow, and your unique plants are counted for you. But first, the science behind the slogan.
What does “eating the rainbow” mean?
Eating the rainbow means eating fruits and vegetables from every color group across the week, because each color can signal a different mix of nutrients and plant compounds. It’s sometimes called the rainbow diet, but it isn’t a diet in the restrictive sense: nothing is cut out. You simply add colors you’re missing.
Here’s what each color brings:
| Color | Foods | What’s behind the color |
|---|---|---|
| Red | Tomatoes, watermelon, strawberries, red peppers | Lycopene, anthocyanins, vitamin C |
| Orange & yellow | Carrots, sweet potatoes, mango, citrus, squash | Beta-carotene, vitamin C, hesperidin |
| Green | Leafy greens, broccoli, kiwi, herbs | Folate, lutein, glucosinolates, fiber |
| Blue & purple | Blueberries, blackberries, eggplant, purple cabbage | Anthocyanins and other polyphenols |
| White & tan | Garlic, onions, mushrooms, cauliflower, oats | Allicin, quercetin, beta-glucans |
Many of the pigments themselves are polyphenols, the plant compounds researchers study for their connections to gut and long-term health. Deeper color can sometimes mean a greater concentration of a pigment, but pale plants bring valuable compounds too. Harvard’s Nutrition Source has a good overview of why variety across fruits and vegetables matters more than any single “superfood.”
Why does eating the rainbow matter?
Variety matters because no single plant carries every nutrient, and because your gut microbes respond to the range of plants you eat, not just the amount. In the American Gut Project, one of the largest published citizen-science studies of the human microbiome, the number of unique plant species people reported eating was associated with microbial diversity. Researchers found distinct microbial patterns when they compared people who ate more than 30 plant types a week with people who ate 10 or fewer.
That finding is where the popular “30 plants a week” goal comes from. It’s an association, not a guarantee, and plant types count generously: fruits, vegetables, whole grains, nuts, seeds, herbs, spices, and legumes all qualify. Coffee counts. So does the basil on your pasta.
The rainbow and the 30-plants goal are two views of the same idea: eat more different plants. Color is just the version your eyes can check at a glance.
How many plants a week should you eat?
Around 30 different plants a week is the most-cited benchmark, based on the American Gut Project’s microbiome findings. There is no official government target for plant variety, so treat 30 as a friendly goal, not a rule. If you’re at 10 today, 15 is a win.
Thirty sounds harder than it is. A smoothie with berries, banana, oats, and flaxseed knocks out four before breakfast! That’s also why Crunchi counts your plants without setting a goal: the number is there for awareness, not another target to hit. Most people are surprised by their count once, then quietly start adding. And since the same colorful foods carry fiber, variety and the basics travel together.
How do you track eating the rainbow?
The easiest way is to let an app like Crunchi count your plants and colors for you, because nobody wants to keep a spreadsheet. Crunchi is a fast, fun macro and fiber tracker that turns your meals into a rainbow of nutrients, and it counts your unique plants automatically.
- Add the meal. Take a photo, scan a barcode, or use the USDA-powered food search.
- Crunchi spots the plants. Every unique plant you eat gets counted across the week, month, and year.
- Watch your palette grow. Your plant count and rainbow fill in together, alongside macros, fiber, and polyphenols.
- Share your wins. Your most colorful meal gets celebrated, not scored.
No color is ever “bad.” A beige day is just a day. Tomorrow is another rainbow.
A rainbow meal example
A bowl with spinach, roasted sweet potato, red pepper, black beans, avocado, and a squeeze of lime covers five color groups and six unique plants in one sitting. In Crunchi, you’d watch the plant count tick up and the arcs fill at the same time.
See your rainbow with Crunchi
Crunchi turns your meals into a rainbow of nutrients and automatically counts your unique plants each week, alongside macros, fiber, polyphenols, added sugar, sodium, and hydration. No calorie counting, no shame.
