Negative calorie foods are those food items that require more energy to digest than they contain. The calorie consumption for digestion of these food items is high than their actual calorie content. It is the logic behind the negative calorie foods. We know that calories are the measure of energy stored in various body parts and food items. Everything we eat contains calories: however, some are empty calories – having low nutritive value.
On the other hand, few foods have high water and fiber content, and we need more calories to digest them. These are negative calorie foods.
Typically, weight loss plans focus on eating fewer calories than our body needs and burning more calories through physical activity. It is the basic logic behind weight loss.
Some foods are getting popular as negative calories and are considered helpful in losing weight.
Here you will come to know what they are and do these foods help you lose weight?
Common negative calorie foods
These are mostly fruits and vegetables. These foods have high water and fiber content.
Some foods that are considered negative calorie foods include:
Celery contains 16 kcal/100 grams and 95% water content. It is rich in cellulose fiber. Our body gets fewer calories from celery because of its lots of undigested cellulose fiber content.
Half a cup of berries like strawberries, blueberries, and raspberries contain almost 32 kcal. Berries also have antioxidant properties.
Tomatoes contain 32 kcal/180 grams and 94% water content. It contains lycopene – an antioxidant that protects the skin from cancer.
It contains 41 kcal/100 grams and has 88% water content. Carrots make a person satiated for a long time and promote weight loss.
Cucumbers have high water content and contain almost 15 kcal/100 grams. It provides fiber content and keeps a person full for a long time.
Watermelon contains 30 kcal/100 grams. It has high water content, and it is one of the best immune-boosting foods.
Apples have 52 kcal/100 grams. These are considered negative calorie food with high vitamin C and fiber content.
Broccoli: 34 kcal/100 grams
Zucchini: 17 kcal/100 grams
Lettuce: 15 kcal/100 grams
Grapefruit: 69 calories/cup
Most of these foods indeed contain fewer calories than others. But there is no evidence to support that more energy is required to digest them. Further research is required to support the idea that these foods actually promote weight loss.
How do negative calorie foods help in weight loss?
It is believed that a negative calorie food requires more energy to chew. Only limited studies support this idea.
Limited research has shown that chewing a piece of gum burns 11 calories per hour. Similarly, chewing a negative calorie food will burn a small number of calories which is relatively unimportant.
Our body indeed uses the calories to digest the food, but this amount is much lesser than the calories food contains. Usually, this amount is calculated as a percentage of calories separately for carbs, fats, and proteins.
For carbs: 5-10% of calories of carbs used to digest or process them
For fats: up to 5% of calories of fats are used to process them
For proteins: 20-30% of the energy used to process proteins
As negative calorie foods have a relatively high amount of water content, little energy is required to process them.
Do negative calorie foods help lose weight?
Proponents claim that eating negative calorie foods helps you lose weight as you require more energy to process them than they actually contain. But this is only a myth. The reality is that you only need 5-10% of your total energy to process the food.
Negative calorie foods such as celery contain high water and fiber content and still require calories to digest. But this energy is much lower than the other high-calorie foods.
The other plant-based diet contains food choices that are not negative calories but still are low-calorie foods.
The bottom line is instead of focusing on few low-calorie foods, incorporate more healthy options into your diet to promote a healthy weight loss.
The bottom line
Negative calorie foods take more calories to process the food than they contain. There is no strong evidence to support this idea. These are actually fruits and vegetables with high water content and are not negative calorie foods.
Though there are no negative-calorie foods still many fruits and vegetables contain low calories with high nutritive value.
Adding a more diverse range of low-calorie food along with healthy fats, carbs or proteins is ideal to promote healthy weight loss and overall wellbeing.