RT Journal Article SR Electronic T1 How to use a controlled fast to investigate hypoglycaemia JF Archives of disease in childhood - Education & practice edition JO Arch Dis Child Educ Pract Ed FD BMJ Publishing Group Ltd and Royal College of Paediatrics and Child Health SP 28 OP 36 DO 10.1136/archdischild-2015-308702 VO 102 IS 1 A1 S Sreekantam A1 M A Preece A1 S Vijay A1 J Raiman A1 S Santra YR 2017 UL http://ep.bmj.com/content/102/1/28.abstract AB Controlled fasts can play a valuable role in the diagnosis and management of hypoglycaemia in paediatric clinical practice, but are no substitute for the collecting of appropriate critical samples at the time of hypoglycaemia for metabolic and endocrine studies. Fatty acid oxidation defects, hyperinsulinism and adrenal insufficiency should always be excluded prior to organising controlled fasts. Controlled fasts are safe if conducted in an experienced setting with strict protocols in place. Failure to adhere to protocol can defeat the purpose of the study and can potentially be dangerous. Proper planning in conjunction with the laboratory and close supervision by staff experienced in controlled fasts is crucial to ensure the best quality information is yielded from these procedures.