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.
