Comparing intermittent fasting and carbohydrate drinks before surgery

Preoperative Intermittent Fasting Versus Carbohydrate Loading to Reduce Insulin Resistance: a Randomised Controlled Trial

NA · Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) · NCT05760339

This study is testing whether intermittent fasting or drinking carbohydrate drinks before surgery helps people with orthopedic issues have better metabolic health.

Quick facts

PhaseNA
Study typeInterventional
Enrollment75 (estimated)
Ages18 Years and up
SexAll
SponsorAcademisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) (other)
Locations1 site (Amsterdam, North Holland)
Trial IDNCT05760339 on ClinicalTrials.gov

What this trial studies

This study investigates the effects of time-restricted feeding (intermittent fasting) versus carbohydrate loading on insulin resistance in patients undergoing orthopedic surgery. Participants in the time-restricted feeding group will follow an 8-hour eating window and a 16-hour fasting period for two weeks prior to surgery, while the carbohydrate loading group will consume a maltodextrin beverage before surgery. The goal is to determine which approach better improves metabolic outcomes around the time of surgery.

Who should consider this trial

Good fit: Ideal candidates are adults scheduled for elective orthopedic surgery who are motivated to adhere to a time-restricted feeding regimen.

Not a fit: Patients with a history of diabetes, eating disorders, or certain other medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved metabolic health and recovery outcomes for patients undergoing orthopedic surgery.

How similar studies have performed: Other studies have shown promising results with intermittent fasting approaches, suggesting potential benefits in metabolic health, but this specific comparison is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Undergoing elective orthopaedic surgery;
* Intermediate, major or complex surgery according to the Surgical Outcome Risk Tool (SORT; http://www.sortsurgery.com/) severity of surgery classification;
* Scheduled for surgery at least 17 days from the date of screening;
* Motivated to follow a time restricted feeding regimen.
* Willing and able to provide written informed consent.

Exclusion Criteria:

* History of diabetes mellitus;
* History of feeding or eating disorders;
* History of delayed gastric emptying or gastro-oesophageal reflux
* Active malignancy
* Patients classified as ASA IV by the attending anaesthetist;
* BMI \< 18.5 or ≥ 35;
* Outpatient or day case surgery;
* Palliative surgery;
* Participation in another clinical trial that is interfering with the procedures or outcomes of the PRINCESS trial;
* Patients unable to fully comply to study needs (e.g. legally incapable patients or patients unable to communicate in Dutch).

Where this trial is running

Amsterdam, North Holland

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Perioperative Care, Intermittent Fasting, Carbohydrate Loading, Preoperative Fasting, Orthopedic Surgery, Insulin Resistance, HOMA-IR, Time Restricted Feeding

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.