The theory of the negative calorie effect of food is based on the idea that certain foods use more calories to be broken down than the number of calories they contain.
These foods are low in calories and high in fibre. The fibre slows down the breakdown and absorption of these foods, also referred to as low GI foods, which keeps an individual feeling full for longer.
The slow rate which fibre-rich foods are broken down ensures the metabolism burns for a longer period of time, which results in the body burning more calories than the food provides due to the low calorie content of negative calories effect foods.
Many people have used negative calorie effect foods in order to kick-start their weight-loss journey. These foods are plant-based and range from vegetables such as asparagus, beetroot, cabbage, spinach, cucumbers, green beans, kale, tomatoes, and zucchini; to fruits such as blueberries, grapefruit, watermelon, cranberries, peaches, strawberries, and raspberries; to spices and herbs such as flax seeds, garlic, ginger, onions, cumin, cinnamon, and mustard seeds.
It is important to include 2 to 3 pounds of these foods, preferably unblended, to your diet daily to benefit from the negative calorie effect.
Blended fruits and vegetables lose a lot of their fibre content – and juicing the fruit and vegetables removes the fibre entirely. This is why it is best to eat the foods raw or lightly steamed as this ensures the fibre remains intact.
There are numerous benefits to consuming these negative calorie effect foods which include a boost in metabolism which ensures the body burns fat as opposed to storing the fat, an increase in energy levels, controlled hunger due to the slow breakdown of the food, stabilised blood sugar levels, improved mood, improved digestion, lowered levels of bad cholesterol in the blood, lowered stress and anxiety levels, increased mental focus, healthier skin, hair, and nails, and improved sleep.
The wide variety of health benefits can be attributed to the high nutrient and mineral content of the foods, which the body requires to function at its best.
Tests have been conducted which measured the metabolic rates of women, who consumed a standard western diet, after they had eaten breakfast and then were tested again, fourteen weeks later, after changing to a plant-based diet which resulted in a 16% rise in the metabolic rate. This is evidence that including large amounts of these foods will speed up the metabolism.
It is important to note that these foods cannot be consumed alongside junk food and be expected to render similar results. The women in the case study also cut dairy, meat, eggs, and fast food from their diet and limited their oil consumption.
There is still debate regarding whether or not these foods do cause a negative calorie effect, or if simply adding these foods to the diet revs up the metabolism which will result in more fat being burned overall. Either way, it is clear that consuming these foods and eliminating non-plant based foods from a diet will turn the body into an efficient fat burning machine.