One kilo of fat = 7700 calories.
If we want to lose 1 kilo of fat we have to burn 7700 calories more than what we will eat.
If we eat 700 calories less every day than we burn, in 11 days we will have lost 1 kg of fat.
The above positioning is too simplistic for reasons of wide understanding.
In fact the metabolism to function normally and burn (and the human body as a whole) needs a huge variety of micronutrients and macronutrients such as: vitamins, minerals & trace elements, high protein high biological value and high absorbency, antioxidants and phytochemicals, carbohydrates and fiber, enzymes, probiotics and prebiotics, plenty of filtered water, Ω3 fatty acids, monounsaturated and polyunsaturated fats.