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A recent study has suggested that we should significantly increase the amount of fruit and vegetables we eat from five a day to at least seven. So how would Michael Mosley do it?

We have known for a long time that eating more fruit and vegetables is likely to be good for us, and the famous five-a-day campaign was always intended as a recommendation aimed at promoting the minimum we should eat, rather than a maximum. What this study adds to things we had previously known is that eating vegetables is better for us than eating fruit (probably because fruit has far more sugar in it) and that eating tinned fruit seems to be positively bad for us (again, probably because it is often in a syrup).

About the author Michael Mosley is a medical journalist, TV presenter and trained doctor

On the basis of this study, you should aim to eat at least four portions of vegetables a day and around three portions of fruit. Importantly, you should eat them, not drink them. The study found no real benefit from drinking fruit juice, and I would say the same is probably true of commercially bought smoothies.

So how do you reach your seven-a-day? If you're feeling continental, you might start the day with an omelette containing a decent handful of spinach. The protein in the eggs will keep you full for longer and spinach is rich in folate and betaine - vitamins that help regulate homocysteine (high levels of which are associated with heart disease). Unfortunately, despite Popeye the Sailor, spinach is not rich in iron.

Alternatively you could add a handful of strawberries or blueberries to your cereal, or wolf down an orange.

A rough guide to portion size The NHS advises a fruit and vegetable portion to weigh about 80g. One fresh apple, banana or peach

Half an avocado

Two handfuls of blueberries

Seven fresh strawberries

One corn on the cob

One medium tomato, or seven cherry tomatoes

Three tablespoons of peas

Two spears of broccoli

Half a pepper

Two-inch piece of cucumber Read the full NHS list here

For lunch and your evening meal you are going to be eating vegetables, with fruit as a dessert. But which vegetables? Again, the recommendations are that you add as much colour as possible to your diet. The different colours of different plants represent some of the thousands of different bioactive compounds, known as phytochemicals, which keep plants alive and healthy.

Eat them raw or lightly steamed rather than boiled to death.

Green

So-called "leafy greens", which include spinach, chard, lettuce and kale, are a good source of minerals like magnesium, manganese and potassium.

Cabbage, cauliflower, broccoli and other members of the brassicas family contain sulphur and organosulphur compounds. Sulphur is essential for the production of glutathione, an important antioxidant, as well as amino acids like methionine and taurine.

Orange and Yellow

Fruit and vegetables with yellow or orange in them are rich in carotenoids. Foods rich in carotenoids include, not surprisingly, carrots. The type of carotenoid you find in carrots can be converted to retinol, an active form of vitamin A. As vitamin A is important for healthy eyesight, this may explain why carrots are supposed to help you see in the dark. Vitamin A also plays an important role in bone growth and regulating our immune system. As well as carrots you will also find carotenoids in melons, tomatoes, peppers and squash.

Red

Another class of carotenoids that produces the colour red are called the lycopenes. You'll find lots of lycopene in rich, red tomatoes. Oddly enough cooking tomatoes actually boosts the levels of lycopene. The reason is that heat helps break down the plant's thick cell walls, making the nutrient more available. Unfortunately heat also destroys vitamin C, so it's a trade off.

Blue and purple

Blue and purple foods get their colouring from a group of flavonoids called anthocyanins. You'll find decent levels of these particular flavonoids in blackberries, blueberries, purple carrots and red cabbage. There is some evidence that anthocyanin - rich blueberries may improve memory and cognitive function in people as they get older.

White

Examples include garlic, white onions, shallots and leeks. These are rich in alliums and allyl sulphur compounds. Although there is no compelling proof that garlic will ward off vampires, it does appear to be quite good at killing microorganisms.

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