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How do we get energy from food and drink?

We all need energy for our bodies to grow and heal and so we can stay active. We get that energy from what we eat and drink.

In this article you can learn:

  • how much energy we get from food
  • how we measure energy from food
  • what Basal Metabolic Rate (BMR) is
  • the difference between simple and complex carbohydrates

This resource is suitable for Health and Wellbeing for primary school learners.

Video - Food as fuel

In this video, different kinds of food are running a race to find out which food is a good energy source. Learn about how different foods fuel our bodies in different ways.

Find out how different foods provide us with energy.

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How do we measure energy in food?

  • We measure energy in .
  • We can work out how much energy our food is giving us by looking at nutrition labels.
  • To find out how much energy food provide, look for kcal or cal on packaging.
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What do we need energy for?

About half of the energy we get from our food is used for things like:

These are all know as bodily functions and are measured using a (BMR).

What is the Basal Metabolic Rate (BMR)?

BMR is the measurement of the energy the body requires to function when it is resting.

Our bodies are amazing. Even when we are physically still, our bodies are busy on the inside and this requires energy. Everyone鈥檚 BMR is at a slightly different rate because we are all unique.

Find out more about our body systems with 2nd level Science.

Physical activity

The rest of the energy is used for physical activities. These range from:

  • very energetic ones like walking, dancing, running, playing football.
  • to less energetic activities like tidying up your bedroom, watching television and even sleeping

The more active you are the more calories you need to consume to keep up your energy levels. Every day we need to eat and drink to replace the energy we have used.

Imagine a car鈥

鈥he more petrol in the tank the further it can drive. Our bodies are no different. We can鈥檛 expect to have energy if we are not eating a healthy balanced diet to fuel them.

Image gallerySkip image gallerySlide 1 of 5, Child walking to school in uniform, Walking to school Our bodies need fuel to walk to and from school so it's important we eat a healthy varied diet to help power those steps. (RayArt Graphics / Alamy Stock Photo)
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How do our food choices affect our energy?

Some foods release energy slowly and others release energy quickly.

Complex carbohydrates

Complex carbohydrates such as bread, apples and corn
Image caption,
Complex carbohydrates release energy slowly. They take longer to digest so they help make you feel fuller for longer. (Tatjana Baibakova / Alamy Stock Photo)

Slow releasing energy foods are called .

  • Complex carbohydrates, also known as starch, can be found in bread, pasta, flour and rice.
  • The wholemeal varieties of these are the healthiest for us because they contain more fibre and less sugar.
  • Complex carbohydrates also include vegetables such as sweet potato, spinach and parsnips.
  • Complex carbohydrates release energy slowly and take time to digest which help us feel fuller for longer.
Complex carbohydrates such as bread, apples and corn
Image caption,
Complex carbohydrates release energy slowly. They take longer to digest so they help make you feel fuller for longer. (Tatjana Baibakova / Alamy Stock Photo)

Simple carbohydrates

Simple carbohydrates such as refined sugar, cake, sweets and ice-cream.
Image caption,
Simple carbohydrates are foods high in sugar, like chocolate, biscuits, fizzy drinks and some fruits. (Yuliya Furman / Alamy Stock Photo)

Fast releasing energy foods are known as .

  • Simple carbohydrates release their calories very quickly.
  • Simple carbohydrates are foods high in sugar.
  • Foods like chocolate, biscuits, fizzy drinks and some fruits give us a quick burst of energy but can then leave us feeling tired and hungry.
  • They can also have an unhealthy impact on our blood sugar levels leaving us feeling overly tired.
  • Although some fruits, like grapes or bananas, are full of natural sugars, they are also full of vitamins, minerals and fibre unlike sweeties.
Simple carbohydrates such as refined sugar, cake, sweets and ice-cream.
Image caption,
Simple carbohydrates are foods high in sugar, like chocolate, biscuits, fizzy drinks and some fruits. (Yuliya Furman / Alamy Stock Photo)
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Test your knowledge

Food and energy quiz

Try the quiz below. Can you work out the difference between slow releasing energy foods (complex carbohydrates) and fast releasing energy foods (simple carbohydrates)?

Challenge - food and energy

  • Choose three foods you can find in your kitchen.
  • Imagine you were running a race.
  • Which out of the three foods would give you the most energy to run the race?
  • Remember you will need slow releasing energy to finish the race.
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