Type 1 diabetes and prolonged fasting

Diabet Med. 2007 Apr;24(4):436-9. doi: 10.1111/j.1464-5491.2007.02098.x. Epub 2007 Mar 15.


Aims: Fasting is common in several religions. The aims of this study were to determine if prolonged fasting (> 25 h) is safe for individuals with Type 1 diabetes and to identify factors associated with success.

Methods: Patients intending to fast were instructed on insulin dose adjustments, frequent glucose monitoring and when to terminate the fast using a standard protocol. Clinical and epidemiological factors were recorded and a comparison was made between successful and unsuccessful fasters.

Results: Of 56 subjects who intended to fast, 37 (65%) were successful. Individuals terminated their fast in the presence of either hypoglycaemia or hyperglycaemia and adherence to the protocol was high. There were no serious side-effects of fasting. Successful fasters had greater reductions in insulin dosage and higher HbA(1c). There were no differences between individuals taking intermittent insulin injections and those with continuous infusion pumps.

Conclusions: Persons with Type 1 diabetes can participate safely in prolonged fasts provided they reduce their usual insulin dose significantly and adhere to guidelines regarding glucose monitoring and indications for terminating fasting.

MeSH terms

  • Adolescent
  • Adult
  • Blood Glucose Self-Monitoring
  • Child
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / therapy
  • Dose-Response Relationship, Drug
  • Fasting / adverse effects
  • Fasting / metabolism*
  • Female
  • Humans
  • Hypoglycemic Agents / administration & dosage*
  • Insulin / administration & dosage*
  • Male
  • Practice Guidelines as Topic*
  • Prospective Studies
  • Religion


  • Hypoglycemic Agents
  • Insulin