VLCD is the acronym of Very Low Calorie Diet (--->'Very Low Calorie Diet'), it refers to a doctor-supervised diet that typically uses commercially prepared formulas to promote rapid Weight loss in patients who are obese.
These formulas, usually liquid shakes or bars, replace all food intake for several weeks or months. VLCD formulas need to contain appropriate levels of vitamins and micronutrients to ensure that patients meet their nutritional requirements. Some physicians also prescribe VLCDs made up almost entirely of lean protein foods, such as fish and chicken. People on a VLCD consume about 800 calories per day or less.
VLCD formulas are not the same as the meal replacements you can find at grocery stores or pharmacies, which are meant to substitute for one or two meals a day. Over-the-counter meal replacements such as bars, entrees, or shakes, should account for only part of one’s daily calories
When used under proper medical supervision, VLCDs may produce significant short-term weight loss in patients who are moderately to extremely obese. VLCDs should be part of comprehensive weight-loss treatment programs that include behavioral therapy, nutrition counseling, physical activity, and/or drug treatment.