The Cleveland Clinic

Weight Loss:
Very Low-Calorie Diets

Traditional weight loss methods include low-calorie diets that allow between 800 to 1,500 calories a day and encourage regular exercise. However, an alternative method that moderately to severely obese people may consider for significant, short-term weight loss is the very low-calorie diet (VLCD).

Many VLCDs are commercially prepared formulas of 800 calories or less that replace all usual food intake. 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. VLCDs are not the same as over-the-counter meal replacements, which are substituted for one or two meals a day.

How Effective Are VLCDs?

A VLCD may allow a severely to moderately obese person to lose about 3 to 5 pounds per week, for an average total weight loss of 44 pounds over 12 weeks. Such a weight loss can improve obesity-related medical conditions , including diabetes, high blood pressure and high cholesterol. However, VLCDs are no more effective than more modest dietary restrictions in the long-term maintenance of reduced weight. Combining a VLCD with behavioral therapy and exercise may increase weight loss and help keep it off for the long-term. Behavioral therapy helps you to recognize what causes you to overeat so that you can consciously change those behaviors.

Are VLCDs Safe?

VLCDs are generally safe when used under proper medical supervision in people with a body mass index (BMI) greater than 30. Use of VLCDs in people with a BMI of 27 to 30 should be reserved for those who have medical complications resulting from their obesity.