No, no food has "negative calories". All foods have calories. But some foods are such that when we eat them, our digestive system use more calories to digest them than the calories the foods actually contain. This is a negative calorie effect. The extra calories needed are used from our body from stored fat. The net effect is a loss of fat from our body resulting in weight loss. Because of this negative calorie effect, these foods may also be termed as fat burning foods.
A wide variety of these negative calorie food items with negative calories properties are available in nature as vegetables and fruits. The list of negative calorie foods gives these food items. The negative calorie foods diet are recommended for overweight and obese people of all ages including children. Normal weight people and children can also include these foods in their daily diet.
You can eat a negative calorie food diet not only for weight loss but also for a good health. This is because the negative calorie foods include a wide range of natural plant foods such as vegetables, fruits, grains, etc. which you can eat daily. You may include as many foods from the list of negative calorie foods as you wish. It will keep your cholesterol and blood pressure under control and avoid the risk of several diseases associated with obesity and overweight.
Conclusion: No diet is actually calorie free negative calorie diet or "negative calorie" food diet. BUT the overall effect of certain foods in our body is that of "negative calories". So these negative calorie foods are said to be effective for weight loss. Incorporate negative calorie foods in diet to lose weight effectively.