Effects of whey protein on health in night shift workers

Effects of an Evening PROtein PrEload on Blood Glucose, Metabolic Health, and Gut Hormone Release in Night ShIfT Workers (PROPENSITy)

Not applicable Interventional University of Adelaide · NCT04869098

This study tests if taking a whey protein supplement can help night shift workers improve their metabolic health compared to a placebo drink.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages35 Years to 65 Years
SexFemale
SponsorUniversity of Adelaide Academic / other
Locations1 site (Adelaide, South Australia)
Trial IDNCT04869098 on ClinicalTrials.gov

What this trial studies

This study investigates the impact of a whey protein supplement compared to a placebo on metabolic health outcomes in night shift workers. Participants will consume either a 30g whey protein preload or a matched placebo drink before their main evening meal for 12 days, with a 2-week washout period in between. Metabolic testing will be conducted at the start and end of each condition to assess changes in health metrics. The study aims to determine if protein supplementation can improve metabolic health in this unique population.

Who should consider this trial

Good fit: Ideal candidates for this study are female night shift workers aged 35-65 with a BMI between 28.0-35.0 kg/m2.

Not a fit: Patients who work standard daytime hours or have a personal history of diabetes or other significant health conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide insights into dietary interventions that improve metabolic health for night shift workers, potentially reducing their risk of type 2 diabetes.

How similar studies have performed: While there have been studies on dietary interventions for metabolic health, this specific approach targeting night shift workers with whey protein is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Female
* Night shift workers (with a minimum of 6 months in their current shift work schedule)
* 35-65 years
* BMI 28.0-35.0 kg/m2; waist circumference \> 80cm
* Weight stable in the past 6 months

Exclusion Criteria:

* Those working standard day time hours only, or those who work less than three to four night shifts per fortnight on average
* Personal history and/or diagnosis of: diabetes, cancer, major psychiatric disorders, liver disease, gastro-intestinal surgery or disease (including malabsorption), eating disorders, anaemia, insomnia or cardiovascular disease, and/or any other condition deemed unstable by the study physician
* Taking medications known to alter body composition or metabolism, including (but not limited to): any medication used to lower blood glucose or antidiabetic medications (metformin, sulfonylureas, Glucagon-like peptide-1 (GLP-1) analogues \[i.e. exenatide\], thiazolidinediones or DPP-IV inhibitors \[i.e. 'gliptins'\]), medications affecting weight, appetite or gut motility (i.e. diuretics, domperidone, cisapride, orlistat, phentermine, topiramate)
* Participants who are taking stable doses (i.e. \> 12 months) of androgenic medications (i.e. testosterone) or SSRI's will not be excluded. Personal history/diagnosis (self-reported) of diabetes (type 1 or 2), major psychiatric disorders (schizophrenia, major depressive disorder, bipolar disorder, eating disorders), gastrointestinal disorders, haematological disorders (i.e. thalassemia, iron-deficiency anaemia) insomnia, or any other medical condition, deemed unstable by the study physician
* Pregnant, planning a pregnancy or breastfeeding
* Those who have lost or gained \>5% of body weight in the last 6 months
* Those who consume four or more standard drinks on a single occasion at a 'daily or almost daily' occurrence
* current smokers of cigarettes/marijuana/e-cigarettes/vaporisers
* unable to comprehend the study protocol (i.e. due to English language or cognitive difficulties)

Where this trial is running

Adelaide, South Australia

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.
Conditions Type 2 DiabetesShift-work Disorder
Last reviewed 2026-06-13 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.