Why five a day: Do you know what your fruit and veg RDA actually does for your health?

A third of children don't know why they need to eat fruit and vegetables, even though they know they should be trying to scoff/force down five a day.

And though most adults are aware that fruits and vegetables are healthy - do we actually know why and what they do?

According to the survey by revision service Education Quizzes, children don't know that fruit and veg is packed with fibre and vitamins and though they know it's good for them, they don't know why - which could go some way to explaining the under 10s' universal distrust of broccoli.

Adults are presumably a little more clued up, knowing that fruits and veggies have vitamins are a great fibre source and full of goodness - but what to they actually do for your body?

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Vitamins and minerals

Often described as 'essential', these are found in abundance in fruit and veg. They're compounds that are used by our bodies for our bodily functions, growth and repair. Each vitamin and mineral has different properties and is used by the body in a different way.

Without them, we can become deficient, meaning our bodies can't work properly and we can develop conditions, illnesses and even have stunted growth and development. For example, without enough vitamin C (found in oranges, kiwis, strawberries, broccoli and potatoes), humans develop scurvy. Vitamin C is needed by the body to make and repair collagen. So without it, humans develop sores, bleeding gums and it can even cause death.

Children who grow up without enough vitamin D have poor bone growth and develop rickets - where the leg bones don't grow properly and bow.

Beyond these well-known examples, there are many other vitamins that we need for everyday functions, from feeling alert and happy to having preventing diseases later in life.

Getting all your recommended daily amount (RDA) of vitamins and minerals is possible from your diet, though many people take supplements.

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Fibre

Fruits and vegetables are packed with soluble fibre. Not only does this keep you regular (pretty important in itself), it also helps keep you feeling full so you don't overeat and has also been shown to protect against some cancers, diabetes and help regulate blood sugar levels as it is digested fairly slowly. It also lower bad cholesterol levels and is thought to protect the heart.

Antioxidants

Antioxidants are important to the body because they protect it against  free radicals, which are damaging atoms in the body that can cause harm to the body's tissues and cells.

Many fruits and veg naturally contain these antioxidants (as do other food and drink such as chocolate and even wine). Good sources are beans, cherries, berries and artichoke.

Ultimately, it's a fact that snacking on fruit and veg is far better for you than biscuits, and as they also tend to have high water content, they're often less calorific than other items of the same size.

Many nutritionists are so keen on promoting the benefits they suggest five a day is a starting point, and actually recommend we aim for more like 10. But perhaps if children could link the benefits to the food they eat in a clearer way they'd be happier to eat their greens.

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The survey also found that young people are lacking basic knowledge when it comes to the link between food and health in general. More than half don’t know that drinking too much alcohol damages the liver and 42 per cent of schoolchildren don’t know why it’s a bad idea to fill your plate with foods that are all the same colour - meaning they could be missing out on essential nutrients.

A third didn't know that exercise strengthens the heart and a quarter didn't know that iron was important for healthy blood.

However, 92 per cent did know to use different chopping boards for raw and cooked foods. Which perhaps suggests that while HE lessons aren't doing a very good job, TV chefs are picking up the slack.