Primely, to lose weight you need to have a negative calorie balance, meaning that you need to consume less calories than your body needs. Yet, negative calorie foods, in theory, require more energy to digest and absorb the food into the body that they have. Therefore, you will burn more calories while digesting those foods, and that will cause you to achieve a negative calorie balance.
Negative calorie foods are mostly fruit and vegetables that contain very little calories and a lot of water. Here are some common examples:
Common examples of negative calorie foods:
Celery: 16 calories per 100g, 95% of water
Grapefruit: 32 calories per 100g, 90% of water
Broccoli: 34 calories per 100g, 89% of water
Tomatoes: 18 calories per 100g, 94% of water
Cucumber: 12 calories per 100g, 96% of water
Watermelon: 30 calories per 100g, 91% of water
Lettuce: 14 calories per 100g, 95% of water
Raspberries: 52 calories per 100g, 85% of water
Lemon: 29 calories per 100g, 88% of water
They all contain very little calories and large amounts of water and fibre. Yet, does the body require more calories to process them than these foods contain?
No, our body needs fewer calories to process them than they contain. It is true that our bodies require energy to chew food, but the amount of energy used during a few minutes of chewing is very small and relatively unimportant. It is also true that the body uses calories to process the food we eat. Most negative calories foods are composed primarily of water and carbs and a little percentage of fat and protein. Therefore, the energy used for digestion is not dramatically higher than for other carb-based foods, which means that only 5-10% of the calories from the foods is used to digest them. Because of this similarity, there’s no scientific evidence supporting the idea of negative calorie foods.
Even if some calories are burned during chewing, digesting and processing foods, it’s a very little percentage of the calories the food provides, therefore negative calorie foods don’t exist. What does exist is little calories food, and that’s what they should be called.
Nonetheless, if the negative calorie food trend is a scam, you should not forget to include those low calories food in your diet, as they are full of nutrients such as vitamins and minerals, and fibre that are beneficial to your health. If you aim to lose weight, try incorporating regular exercise as well as a healthy diet, rather than following new diet trends.