IWhen you’re on a low calories diet, you usually get between 800 and 1,500 calories a day. For some people, an alternative for short-term weightloss is a very low calories diet.
Many very low calories diet are commercially-made formulas of 800 calories or fewer that replace all the food you usually eat. Others, such as the well-known grapefruit diet (also called the Hollywood Diet), rely on eating a lot of the same low-calorie food or foods.
Very low-calorie diets are not the same as over-the-counter meal replacements, which you substitute for one or two meals a day.