Variety isn’t just the spice of life, but the cornerstone of health, especially when it comes to nutrition. The concept of “eating a rainbow” encourages us to fill our plates with fruits and vegetables of every colour, and there’s a good reason for this advice. But what do these mean for you?
The science behind the rainbow
The vibrant colours in fruits and vegetables come from pigments such as carotenoids, flavonoids, betalains, and chlorophylls, all representing a variety of bioactive compounds called phytonutrients that have unique health benefits, from fighting inflammation to reducing the risk of chronic diseases.1,2
Each colour corresponds to specific phytonutrients. For example:2
Red foods, like tomatoes and red peppers, are rich in lycopene, a powerful antioxidant linked to heart health and reduced cancer risk.
Orange and yellow foods, such as carrots and sweet potatoes, are loaded with beta-carotene, which supports eye health and boosts the immune system.
Green vegetables, like spinach and broccoli, contain chlorophyll and lutein, which improve eye health and may reduce the risk of some cancers.
Blue and purple foods, like blueberries and aubergines, are high in anthocyanins, which support brain health and combat inflammation.
White foods, including garlic and cauliflower, are packed with flavonoids and allicin, known for their heart-protective and immune-boosting properties.
Why colour variety matters
Studies show that a diverse diet of colourful fruits and vegetables provides more comprehensive health benefits than focusing on quantity alone.1,2 Consuming a range of pigments is associated with improvements in cardiovascular health, reduced inflammation, better weight management, and even a lower risk of type 2 diabetes and cancer.
For instance, a study found that people eating minimally processed, colourful foods naturally consumed fewer calories and felt more satisfied compared to those eating ultra-processed meals, despite similar calorie counts.3 This is because nutrient-dense, colourful foods are more satiating and beneficial to your gut microbiome.
The role of the gut microbiome
Your gut microbiome—the community of trillions of microorganisms in your digestive system—plays a critical role in how your body processes and absorbs nutrients. A diverse intake of fruits and vegetables supports a healthy microbiome, which can enhance digestion, reduce inflammation, and even influence how many calories your body absorbs.
Additionally, monotony in your diet can result in a “phytonutrient gap,” where you miss out on the diverse benefits offered by different pigments.2 Research indicates that most people fall short in consuming phytonutrients from every colour group, with blue and purple foods being the most neglected.1,4
Practical tips for a rainbow plate
Incorporating more colours into your meals doesn’t have to be complicated. Here are some simple strategies:
Include at least three colours on your plate at every meal. For example, a salad with spinach (green), cherry tomatoes (red), and grated carrots (orange).
Swap your usual choices for less common options like purple cauliflower or yellow watermelon.
Seasonal fruits and vegetables are often more flavourful and nutrient-rich.
Smoothies are an easy way to combine a variety of colourful fruits and vegetables in one go.
The numan take
Eating a rainbow is about more than just boosting your nutrient intake; it’s a step towards a sustainable, balanced lifestyle. A colourful diet promotes long-term health, supports your immune system, and may even improve mental wellbeing. Plus, it encourages mindfulness about what you’re eating, transforming meals into an opportunity to nourish your body.
References
Minich DM. A review of the science of colorful, plant-based food and practical strategies for ‘eating the rainbow’. J Nutr Metab [Internet]. 2019;2019:2125070. Available from: http://dx.doi.org/10.1155/2019/2125070
Blumfield M, Mayr H, De Vlieger N, Abbott K, Starck C, Fayet-Moore F, et al. Should we ‘eat a rainbow’? An umbrella review of the health effects of colorful bioactive pigments in fruits and vegetables. Molecules [Internet]. 2022;27(13):4061. Available from: http://dx.doi.org/10.3390/molecules27134061
Hall KD, Ayuketah A, Brychta R, Cai H, Cassimatis T, Chen KY, et al. Ultra-processed diets cause excess calorie intake and weight gain: An inpatient randomized controlled trial of ad libitum food intake. Cell Metab [Internet]. 2019;30(1):67-77.e3. Available from: http://dx.doi.org/10.1016/j.cmet.2019.05.008
Siddiqui SA, Azmy Harahap I, Suthar P, Wu YS, Ghosh N, Castro-Muñoz R. A comprehensive review of phytonutrients as a dietary therapy for obesity. Foods [Internet]. 2023;12(19). Available from: http://dx.doi.org/10.3390/foods12193610
