Medical Considerations

Before Beginning: is it right for you?

Before starting a VLCD program, it is important that you are assessed by a Healthcare Professional for any evidence of pre-existing medical conditions.

Who Is Not Suitable?

Pregnant women

Pregnant women are not suited to commence Proslim VLCD because they should not be intentionally trying to lose weight as this could affect the growth and development of the baby.

Breastfeeding women

Breastfeeding women require extra nutrients to provide a good quality and quantity of breast milk and this can be affected if they lose a large amount of weight. Breastfeeding women should wait until they have finished breastfeeding before commencing Proslim VLCD.


Weight loss programs are not recommended for children under 18 unless approved and supervised by a Healthcare Professional.


Rapid weight loss may not be suitable for the elderly due to the possible side effects, pre-existing health conditions and increased medication needs.

Complex medical conditions

Rapid weight loss is not suitable for those that have complex medical conditions such as;

  • Porphyria (metabolic disorder)
  • Liver or kidney disease
  • Type 1 diabetes
  • Haemopathy (disease of the blood)
  • Cancer
  • Electrolyte disorders
  • Acute cardiovascular or cerebrovascular disease
  • Unstable angina
  • Hereditary metabolic disease
  • Psychological disturbances of more than a minor degree, including schizophrenia
  • Behavioural disorders involving eating (anorexia or bulimia), alcoholism or drug addiction
  • Major surgery or serious accidents within the last three months
  • Gout
  • Gallstones
  • Kidney stones
  • Acute ischaemic cardiopathies (heart problems)

Possible Side Effects

During the first few days of the diet, you may experience symptoms such as;

  • Headaches
  • Bad Breath
  • Nausea
  • Dizziness
  • Hunger
  • Diarrhoea
  • Tiredness
  • Constipation
  • Feeling Cold

These are expected as the body adjusts to using fat stores as an energy source. The symptoms normally improve after 2-4 days. Keep your fluid intake up. If constipation becomes a problem, supplement the diet with a fibre supplement and increase fluid intake. Bad breath can be refreshed by chewing sugar-free gum or low calorie mint. Dizziness, fatigue and headaches can be reduced by drinking the advised additional 2 litres of water daily.

Medication Considerations

It is important that you inform your Healthcare Professional if you have any medical conditions or are taking medication before beginning the program. Some medications require limiting of certain vitamins and minerals to prevent them interfering with absorption eg. Some thyroid patients need to limit their iodine intake. Whilst following a VLCD program, some people may become more sensitive to their medication. Anyone taking medication should be monitored more frequently as the dosage of some medications such as high blood pressure and high cholesterol medication may need adjusting as weight is lost. This is especially important in the early stages of weight loss.