There is no such thing as a negative calorie – a calorie is a unit of heat and it cannot be negative. So when populace converse about negative calorie foods, this just means a food whose calorie level is stumpy enough taking more energy to eat and absorb it than the food contains. But there are very few foods like this.

Negative calorie diet is a form of fasting or detox, provided that you are otherwise healthy, this can be a great way to clean out the system.

Keep the following points in mind if you will be using this as detox diet:

1. It is never a good idea to eat huge quantities of one type of food, especially fruits.

A lot of foods contain substances that can be damaging if consumed to excess.

For example, the acid in grapefruit and pineapple can damage your stomach lining. Other foods put an excessive burden on the liver or may cause diarrhea. So try to use all the different foods in small quantities.

2. Do not spend all day eating.

You will just become bloated and feel sick. If you are only doing this for a couple days, you should not feel too hungry. Plan four or five salad meals each day, and let your digestion rest at other times.

3. You will feel more satisfied if you eat slowly and chew your food thoroughly.

You will also use more calories that way. So if the foods can be eaten raw, that will be more effective than cooking them.

Foods like carrots and beets will also be more satisfying if you eat them grated.

4. Schedule time when you do not have any important commitments.

As with fasting or any kind of detox, you may suffer some uncomfortable symptoms including headaches, tiredness, depression and irritability. If these become severe, stop the diet and see a doctor.

5. When you end the detox, plan a gradual return to normal eating.

If all the above points are checked and passed, below is the list of negative calorie foods:

* Apples
* Asparagus
* Beets
* Blueberries
* Broccoli
* Cantaloupes
* Carrot
* Cauliflower
* Celery stalk
* Celery root
* Cranberries
* Cucumbers
* Eggplant
* Endives
* Garden cress
* Garlic
* Grapefruit
* Green beans
* Green cabbage
* Lamb’s lettuce
* Lemons
* Lettuce
* Onions
* Papayas
* Pineapples
* Prunes
* Radishes
* Raspberries
* Spinach
* Strawberries
* Tangerines
* Tomatoes
* Turnips
* Zucchini