Nutrition: fun facts and quiz

Food supplies carbohydrates for energy, proteins to build and repair the body, fats, vitamins, minerals, fibre and water.

Key fact
No single food provides everything we need.

Vitamins are small nutrients the body needs to work well. Vitamin C helps heal wounds, and vitamin D, made in the skin in sunlight, helps build strong bones.

Key fact
Sailors once got scurvy on long voyages, from a lack of vitamin C.

Water makes up about 60% of an adult’s body. We lose it by breathing, sweating and going to the toilet, and replace it with drinks and food.

Key fact
About a fifth of our water comes from food.

Fibre is the part of plant foods we can’t fully digest. It keeps digestion moving and feeds helpful gut bacteria. Wholegrains, beans, fruit and vegetables are rich in it.

Key fact
Most adults eat less fibre than recommended.

Small amounts of sugar and salt are fine, but many processed foods hide a lot of both. A single can of cola can contain around 35 g of sugar, about 9 teaspoons.

Key fact
Checking labels reveals hidden sugar and salt.

Trillions of microbes live in your gut, helping digest food, make some vitamins and train the immune system. A varied diet feeds a varied microbiome.

Key fact
Yoghurt and other fermented foods contain live microbes.

Some food beliefs don’t hold up. Carrots don’t give you night vision, and eating late doesn’t by itself make you gain weight: what you eat over the day matters more.

Key fact
The carrot story was boosted by British wartime propaganda.