Although Very Low Calorie Diets (VLCD) taken during drastic dieting can show some positive effect for short-term weight-loss, they are not satisfactory for long-term maintenance of body weight. In most cases, it becomes impossible to remain on VLCDs for long, so people tend to binge thus putting on weight or suffer from side-effects. Common complaints include fatigue, headaches, constipation, nausea and irritability……...click & see
On a more serious note are Inflammation of intestine and pancreas, low BP, cardiac arrhythmias, kidney stones and if prolonged for a longer period can lead to death. Those with clinical complications like diabetes, cardiac ailments or metabolic disorders, should remember to avoid VLCDs as the consequences may be detrimental and aggravate their problems.
Source:The Telegraph (Kolkata,India)