23 foods that contain NO calories

It's that time of year when many of us are counting calories and making sure we don't eat more than we really need to.

But some foods are guaranteed to make you feel free from any guilt as you'll burn more calories by chewing and digesting them than you'll consume.

While most people know celery is one of these super-healthy zero calorie foods, some others on the list may surprise you - including strawberries and swede.

Some foods are guaranteed to make you feel free from any guilt as you'll burn more calories by chewing and digesting them than you'll consume - including apples

From apricots to asparagus, and garlic to grapefruit, these very healthy snacks are what are known as 'zero-calorie foods', according to experts.

And when eaten in moderation, they will not contribute to your daily calorie total, it's said.

1. APPLES

Calorie content: 47 kcals per 100g

As the old saying goes, an apple a day keeps the doctor away - and there may be some truth to it. Apples are packed full of important vitamins such as C, and A and can promote heart health.

2. APRICOTS

Calorie content: 12 kcals per apricot

Eating apricots is said to help reduce the risk of strokes, and heart attacks. They're also full of vitamin C, potassium and dietary fibre, which all promote good heart health.

3. ASPARAGUS

Calorie content: 6 kcals per spear

As well as being packed with antioxidants, it contains lots of essential vitamins such as A, C, E and K along with plenty of fibre.

4. BEETROOT

Calorie content: 36 kcals per 100g

Beetroot is a good source of iron and folate as well as containing plenty of antioxidants. It's also been said to lower blood pressure, boost exercise performance and prevent dementia.

5. BROCCOLI

Calorie content: 33 kcals per 100g

Broccoli is a great source of vitamins K and C, and also has lots of potassium and fibre. It also contains plenty of the powerful antioxidant Vitamin C which is said to help cuts heal quicker and fight off diseases such as cancers.

6. CAULIFLOWER

Calorie content: 3 kcals per floret

One serving of cauliflower is said to contain 77 per cent of an adult's daily recommended allowance for vitamin C. The vegetable is also a great source of other important vitamins.

7. CELERY

Calorie content: 2 kcals per stick

It's mainly water which is why you'll burn more calories than consume them when you eat this vegetable.

8. CRANBERRIES

Calorie content: 15 kcals per 100g

These red fruits are another great source of vitamin C, as well as fibre, manganese, and plenty of antioxidants.

9. WATERCRESS

Calorie content: 4 kcals per quarter of a bunch

Watercress is thought to have medicinal properties and contains particularly high levels of vitamin K - important for bone health - and vitamin A (eye health). It also contains glucosinolate compounds, which have been found to have anti-cancer properties.

10. CUCUMBER

Calorie content: 6 kcals per 1 inch piece

This vegetable is mostly water, and helps to flush out toxins from the body, say health experts. It also helps you stay hydrated, and contributes to both heart and eye health.

11. FENNEL

Calorie content: 12 kcals per 100g

As well as containing lots of fibre, it is thought that fennel helps to rebalance the female sex hormones blamed for some of the symptoms of PMT.

12. GARLIC

Calorie content: 49 kcals per 100g

It won't be zero calorie if you eat too much of it, but you'll burn off more calorie than you consume if you eat one clove, it's said.

13. GRAPEFRUIT

Calorie content: 24 kcals per half a grapefruit

A study has found that drinking grapefruit juice when eating fatty food lowers the amount of weight put on by up to a fifth.

14. GREEN BEANS

Calorie content: 24 kcals per 100g

Eating green beans will help you get a flat stomach, according to some nutritionists. It's packed full of essential vitamins and vitamins, as well as some protein too.

15. KALE

Calorie content: 33 kcals per 100g

There are dozens of claims about the cancer-beating properties of kale, and while some nutritionists say eating broccoli and brussels sprouts is actually better for you, the vegetable still contains plenty of essential vitamins.

16. LEEKS

Calorie content: 22 kcals per 100g

Leeks are an excellent source of vitamin K as well as manganese, vitamin B6, copper, iron, and vitamin C.

17. LEMONS

Calorie content: 3 kcals per slice

When life gives you lemons... just eat them. A slice contains just three calories, meaning you'll burn more or the same number - making it a zero calorie food in moderation.

18. LETTUCE

Calorie content: 14 kcals per 100g

Made up of mostly water, a lettuce leaf won't contribute to your daily calorie intake.

19. ONION

Calorie content: 7 kcals in one slice

Every recipe book will contain more than a few recipes containing this staple ingredient, but in moderation, you'll burn more calories by eating that than you consume.

20. RASPBERRIES

Calorie content: 1 kcal per raspberry

Raspberries contain very high levels of vitamin C, and it's said that eating them could help to boost fertility.

21. STRAWBERRIES

Calorie content: 3 kcals per fruit

Strawberries contain more vitamin C than the equivalent amount of oranges and have been said to aid digestion.

22. SWEDE

Calorie content: 24 kcals per 100g

Swedes are low in calories, making them an ideal food for slimmers. They supply a reasonable amount of vitamin C - about 20 per cent of the RDA in an 85g cooked portion - as well as some beta-carotene for a healthy immune system.

23. WATERMELON

Calorie content: 16 kcals in a quarter of a slice

It's said this fruit could help hydrate you just as much as a glass of water can, and it's also reported to prevent heart attacks and weight gain because it halts the build-up of bad cholesterol.