Patient Suitability


Age >65 years

The OPTIFAST VLCD Program Intensive level is not recommended for use in persons over the age of 65 years, as metabolic and physiologic adaptations to intensive diets are decreased.

However under conditions in which rapid weight loss is considered to be lifesaving a modified OPTIFAST VLCD Program may be prescribed under medical supervision. Care must be taken to ensure nutritional requirements are met such as increased protein and requirements for certain vitamins and minerals.

History of severe psychological disturbance, alcoholism or drug abuse

Individuals diagnosed with psychosis should only proceed with a VLCD diet under the guidance of their medical practitioner.

The medical practitioner must weigh up the benefits versus the risks. The psychotic state may lead to inappropriate and/or unreliable use of the VLCD placing the patient at nutritional risk.


Rapid weight loss may induce the formation of gallstones. Where fat intake can sometimes be low with a VLCD, the addition of fat (i.e. 1 tsp vegetable oil per day) to the VLCD program can stimulate the emptying of the gall bladder and can prevent the formation of gallstones. Formation of gallstones can also be prevented with ursodeoxycholic acid.


Gallbladder problems may be associated with pancreatitis and/or cholangitis. In patients with a suspected history of cholecystitis or gallstones, the potential for the development of pancreatitis must be considered and reviewed with the patient.

Isolated acute pancreatitis has been reported only rarely during weight reduction, however with a patient complaint of severe abdominal pain and/or elevated amylase or alkaline phosphatase, pancreatitis and/or cholangitis should be considered. If confirmed, the patient should be advised to postpone weight reduction until the condition is treated and resolved.


Although the OPTIFAST VLCD Program contains adequate electrolytes for most individuals, some individuals may become hyponatraemic or hypokalaemic, especially if they are receiving diuretic therapy. In such circumstances, electrolyte supplements may be required or diuretic therapy reduced or stopped.


Serum uric acid increases during the first weeks on a VLCD. Despite this, attacks of gout are rare although patients with a history of gout may occasionally develop an acute attack. In patients with a history of gout it is important to ensure an adequate fluid intake, and the addition of allopurinol 300mg daily may be considered.

Liver Enzymes

Transient elevations of hepatocellular enzymes may occur through the Intensive Phase of the program, but progressive elevation beyond three times the upper limit is abnormal and unusual. Elevations of liver enzyme values (SGOT, SGPT, ALT, GGT) occur in a significant number of morbidly obese patients. Sometimes such elevations are present at baseline and decrease to normal during weight loss.

Isolated elevations of hepatocellular enzymes and the absence of significant elevations of bilirubin, alkaline phosphatase or findings of acute disease, may not require further investigation or changes in dietary protocol. Significant elevation of bilirubin and/or alkaline phosphatase and gamma glutamyl transpeptidase (GGT) with a progressive elevation of hepatocellular enzymes suggest intercurrent hepatic disease, such as hepatitis or pancreatitis and must be investigated.

Women Menstrual cycle changes

Women may experience a variety of changes in their menstrual cycle during weight loss. Cycles may resume or decrease with weight loss and generally return to normal following re-feeding.


Women previously infertile (due to polycystic ovarian syndrome PCOS) may ovulate and become fertile while on a weight loss program. Women should be informed and should take appropriate birth-control precautions. Women must avoid the ‘Intensive Level’ of the OPTIFAST VLCD Program whilst trying to conceive.

Diaphragm Usage

Women who are using a diaphragm for birth control may need to be referred to their Obstetrician/Gynaecologist for periodic checks on the fit, since fit may change as the patient loses weight.