What is a hypocaloric diet?
A low-calorie diet is a diet in which you consume fewer calories than your body uses.
That is, if your body burns 2500Kcal and you only eat 2000Kcal, you are following a low-calorie diet.
What a low-calorie diet is for you may not be for your colleague next door.
It is important to know the calories you use daily, as person A can spend 2000Kcal per day and person B 3000Kcal per day, a 2500Kcal diet will be hypercaloric for person A and hypocaloric for person B.
Low-calorie diets are used to lose fat/weight.