You will find a free list of negative calorie foods below, but first let's consider what this means. There is no such thing as a negative calorie - a calorie is a unit of heat and it cannot be negative. So when people talk about negative calorie foods, this just means a food whose calorie level is low enough that it takes more energy to eat and digest it than the food contains.

For example, if you consider water to be a food, then cold water is certainly a negative calorie food. It contains no calories at all and the body has to expend energy to bring it up to blood temperature. So every time we drink a glass of cold water we burn up a couple of calories and lose a little weight. But there are very few foods like this. Most foods that are on the list do not really use more calories than they add, or if they do the effect is negligible ... until you remember that at the same time the body expends energy just to keep alive and breathing. Celery for example does not give us enough calories to cover both the energy that it takes to digest it, plus the energy that we expend even when we are doing nothing. So that is why people call it a negative calorie food.

Negative calorie foods are most attractive to anorexics. A negative calorie diet would obviously result in starvation in the long term and nutritional deficiencies can occur surprisingly quickly. The calories burnt usually come from muscle mass, and the result is debility and wasting.

A more healthy way to use a negative calorie diet is as a form of fasting or detox. It is something you can do for one to three days right after the Christmas season or another time when you have been eating a over-rich diet. Provided you are otherwise healthy it can be a great way to clean out the system. However it is still best to take medical advice before attempting this.

If you decide to use a negative calorie detox, keep the following points in mind:

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, let's move on to the list of 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

Please use this free list of negative calorie foods wisely.