Eat a Rainbow Diet by Fiona Kirk

By Fiona Kirk, nutritionist and author of ‘So What The F*** Should I Eat?’

When it comes to diets and health, Fiona can rant for Britain! Particularly about the crazy lengths to which some will go to lose weight. Confusion reigns supreme which is why she decided to write a book. ‘So What the F*** Should I Eat?’ is not a diet book as such; deprivation, frustration and denial make us miserable, tired and hungry and have no place at her table. When we learn how to eat, live and love good food and address our own priorities it is a great deal easier to body-swerve the wealth of diet nonsense that is coming at us from all sides and find the fit, healthy individual we know is lurking somewhere under the pounds of excess flesh!

Eat a Rainbow Diet

If I told you that eating one apple, one onion, one orange, a handful of spinach, a grilled tomato, a small green salad, a few florets of broccoli and a bowl of mixed berries every day would ensure you live to a healthy 100 years old, avoiding cancer, heart disease and a host of degenerative diseases along the way would you believe me? And, more importantly would you do it?

It was originally thought that it was only the vitamin and mineral content of fruits and vegetables, along with the all-important fibre, that conferred extensive health benefits. But these are exciting times in the fruit and vegetable research world and the focus is swinging big time to the importance of their protective phytochemical compounds. There are literally tens of thousands of these little gems present in the plant kingdom and by unlocking their antioxidant, anti-inflammatory, anti-bacterial and immune-boosting properties, daily discoveries are being made about their health-enhancing greatness.

Rainbow of Fruit
Rainbow of fruit – Photograph by Mary-Lynn

FACT: A diet rich in fruits and vegetables is our best bet for delaying/preventing virtually every chronic disease. This has been established time and again by scientific study. The evidence is so strong that it has been endorsed by UK and US government health agencies, the WHO (World Health Organisation) and virtually every major medical organisation.

Unless you have been living on another planet, it is hard to claim ignorance of the 5-a-Day recommendation and yet the daily average in the UK wobbles somewhere around 2.7 portions for women, 2.5 portions for men and a mere ONE A DAY for teenagers! It’s all doom and gloom from a health point of view!

But, why was the number “5” selected as the UK goal when the Australian government recommends 7, Greece 9 and in the US, The National Cancer Institute says the minimum should be 5 for children, 7 for women and 9 for men? The French have gone one better and recommended 10! It appears to be something to do with us being such poor fruit and vegetable eaters that 5 was deemed achievable. Sadly, even 5 seems to be a step too far. So why are they so hateful, why do we resist them? They come in every colour of the rainbow and if we removed them from the supermarket shelves it would be a bleak place. Many of them can be enjoyed raw or cooked, they are as easily transported as a packet of crisps and the variety of dishes we can concoct with them is almost limitless.

Enter the Phytochemicals!

But, what exactly are they? They are a plant’s security blanket and when consumed in our diet, offer the same security and protection. The content, concentration and distribution of phytochemicals in any plant depends upon the species, the soil in which it grows, climatic conditions, degree of ripeness and its cultivation and storage. But why is colour so important? Many of these versatile phytochemical compounds are concentrated in the leaves, skin and peel and their bright colours attract insects and birds for pollination and seed dispersal which is vital for continuation of the plant species. They are also concentrated in the core of the plant, in the pips and seeds to protect their precious genetic material, their DNA. All too often peel and pips are discarded during industrial processing resulting in a vastly reduced dose. So, wherever possible, wash/scrub your fruits and vegetables and enjoy them as nature intended – fresh, raw or lightly cooked.

1 + 1 + 1 + 1 + 1 Does Not Always Equal 5!
It is impossible to cover all the properties and the perceived health benefits of the vast number of these phyto ‘giants’ currently hitting the headlines on the back of numerous research studies, but one thing is becoming crystal clear. The broader the range, the greater the protection. Whilst certain fruits and vegetables have benefited from more research and press than others (broccoli, blueberries, pomegranates to name but three) there is no singular super food that is going to bring about super health. The body demands a balance of ‘macro’ nutrients in the form of carbohydrates, proteins and fats, a balance of ‘micro’ nutrients in the form of vitamins and minerals and a balance of ‘accessory’ nutrients in the form of phytochemicals etc. in order to energise, repair and regenerate. Having 5 punnets of blueberries every day won’t provide the balance. Variety is the key.

Here are some to look out for. Don’t let the science confuse, just pack as many of them in whenever you can:- carotenoids, flavonoids, polyphenols, lycopene, quercetin, resveratrol, allicin… Think of them as a fabulous and health-enhancing injection of colour into your life!

Carrots – Photograph by Darya Pino

Orange Fruits + Vegetables
Apricots, cantaloupe melon, mango, nectarines, oranges, papaya, peaches, tangerines, butternut squash, carrots, pumpkin, sweet potatoes.

Rich in phytochemicals known as carotenoids. A number of studies have found higher blood levels of these carotenoids to be associated with significantly reduced thickening of the arteries leading to an increased risk of cardiovascular disease.

Purple Potatoes
Purple Potatoes – Photograph by Tracy O

Red Fruits + Vegetables
Red apples, blood oranges, cherries, cranberries, red grapes, pink grapefruit, red pears, pomegranate, raspberries, strawberries, watermelon, red beets, red peppers, red cabbage, radishes, red onions, red potatoes, rhubarb, tomatoes.

This group contains phytochemicals such as lycopene and anthocyanins and may maintain heart health, memory, urinary function and reduce cancer risks. The results of studies suggest that lycopene-rich diets are associated with significant reductions in the risk of prostate cancer. Heating tomatoes in oil has been shown to increase its effectiveness. Ellagic acid which is present in many red fruits and berries, particularly raspberries has antioxidant and anti-cancer properties. Studies have also shown the anti-cancer activity on cancer cells in the breast, oesophagus, skin, colon and pancreas.

Yellow Fruits + Vegetables
Lemons, yellow pears, pineapple, yellow peppers, corn, summer and winter squash, yellow tomatoes, yellow apples, turnips.

This group contains antioxidants, vitamin C, carotenoids, and bioflavonoids and may reduce the risks of cancer, increase heart health, vision and immunity. Beta-carotene is a yellow pigment naturally occurring in fruits and vegetables. In plants, it acts as an antioxidant and neutralises damaging free radicals. Cooking improves the availability of carotenoids in foods.

Green Fruits + Vegetables
Lettuce, watercress, courgettes, green beans, green peppers, avocado, green apples, honeydew melon, kiwi, limes, pears, artichokes, asparagus, spinach, sugar snap peas, broccoli, Brussels sprouts, cabbage, celery, cucumber, peas

Lutein and zeaxanthin are by far the most researched phytochemicals in this group. By preventing a substantial amount of the blue light entering the eye from reaching underlying structures involved in vision, these phytochemicals may protect our eyes from light-induced oxidative damage which is thought to play a role in age-related macular degeneration. The available scientific evidence suggests that consuming at least 6mg per day may decrease the risk.

Greenish/White Fruits + Vegetables
Bananas, dates, white peaches, cauliflower, chives, fennel, garlic, ginger, spring onions, Jerusalem artichokes, leeks, mushrooms, onions, parsnip, potatoes, shallots.

This group contains phytochemicals such as allicin, found in the garlic and onion family and quercetin, which is particularly rich in apples, onions, cauliflower and cabbage. These may reduce the risks of heart problems and cancer, help maintain a healthy level of blood cholesterol and help control blood pressure. Quercetin also inhibits the release of histamine, which causes congestion and studies have also shown an improved lung function and lower risk of certain respiratory diseases (asthma and bronchitis) for people with high quercetin intake. Recent studies have also shown a reduction in the cancer risk of prostate, ovary, breast, gastric and colon cells.

Prunes and Plums
Prunes and Plums – Photograph by

Blue/Indigo/Violet Fruits + Vegetables
Blackberries, blueberries, blackcurrants, figs, purple grapes, plums, prunes, raisins, purple broccoli, aubergine, purple potatoes.

Rich in a class of phytochemicals best known as flavonoids, which have been the subject of extensive research. Flavonoids protect plants from oxidative damage and perform the same function for humans. The colours blue, purple and violet seen in berries, grapes and aubergines are due to their phenolic content. The outstanding feature of phenols is their ability to block specific enzymes that cause inflammation. This anti-inflammatory action may reduce cancer risks and help to maintain urinary tract health and memory function. Resveratrol, found in grapes, grape juice, wine, blueberries, bilberries and cranberries has received a great deal of attention for its French Paradox connection. In essence, it appears that although the French eat a diet relatively high in saturated fat, they show much reduced rates of coronary heart disease when compared with northern European nations. The most popular explanation, backed by numerous ongoing studies is that their relatively high consumption of red wine offers some protection.

Getting Phytochemicals Into Your Daily Diet

  • Make sure your shopping basket is full of colour
  • Juice a couple of fruits every day – it takes a matter of minutes
  • Steam a bag of mixed vegetables, drizzle with olive oil and lemon juice and eat while you are preparing supper
  • Fill at least half your plate with salad/vegetables, then serve the remainder of your meal
  • Keep fruit and raw baby vegetables in your handbag/briefcase to snack on every couple of hours
  • Keep a fruit bowl where you can see it and regularly refill
  • Always have a pot of vegetable soup simmering and make it as colourful as possible
  • Experiment with cooking methods for both fruits and vegetables – steam, grill, bake, roast, kebab, puree (the internet is bursting with suggestions)

And try this!
There are 7 days in every week! Use the lists above, go for a different colour every day for a week and chart how many ways you can get that colour into your diet each day AND experiment with fruits and vegetables you may be unfamiliar with. Chop them, shred them, grate them, juice them, puree them, mash them, add them to soups, stews, stir fries, pasta, rice, stuff them in wraps and pitta pockets, dip them in oils and salsas and ENJOY!