How men and women metabolize a high-fat breakfast differently

Exploring Sex Differences in the Acute Postprandial Metabolic Response to a High-fat Mixed Macronutrient Meal Challenge in Healthy Young Humans

Not applicable Interventional McMaster University · NCT05332301

Researchers will test whether healthy young men and women process a single high-fat breakfast differently in the hours after eating.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment24 (estimated)
Ages18 Years to 35 Years
SexAll
SponsorMcMaster University Academic / other
Locations1 site (Hamilton, Ontario)
Trial IDNCT05332301 on ClinicalTrials.gov

What this trial studies

Investigators will give a single high-fat “fast-food” style breakfast (846 kcal; 58% of calories from fat) to 24 healthy young adults (12 men and 12 women) aged 18–35. Eligible participants must be weight-stable, have BMI 18.5–30 kg/m2, be non-smokers, not pregnant or breastfeeding, and not using hormone-altering contraceptives. Blood and metabolic measurements (including glucose, insulin, non-esterified fatty acids, lipid measures, and substrate oxidation) will be taken over the hours after the meal to compare postprandial responses between sexes. The controlled, acute feeding protocol aims to reveal early metabolic differences that could help explain longer-term sex differences in diet-induced insulin resistance.

Who should consider this trial

Good fit: Healthy adults aged 18–35 with BMI 18.5–30 kg/m2 who are weight-stable, non-smokers, not pregnant or breastfeeding, not using hormone-altering contraceptives, and able to attend in-person testing at McMaster University are ideal candidates.

Not a fit: People with diabetes, other metabolic disorders, cardiovascular or gastrointestinal disease, smokers, those with PCOS, pregnant or breastfeeding persons, vegans/vegetarians, users of hormone-altering contraceptives, or those outside the specified age/BMI ranges are unlikely to receive direct benefit from participation.

Why it matters

Potential benefit: If successful, the results could clarify why women are less prone than men to diet-induced insulin resistance and help tailor sex-specific dietary guidance to reduce diabetes risk.

How similar studies have performed: Prior work has shown mixed acute glucose responses to high-fat meals and greater insulin responses in obese versus lean subjects, but direct acute comparisons between men and women using a standardized high-fat challenge are essentially novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* BMI between 18.5 and 30.0 kg/m2
* Weight stable for the past 6 months (± 2kg)
* Exercise at or below the Canadian Physical Activity Guidelinesa
* Fasting blood glucose \<6.0 mM
* Resting blood pressure \<140/90 mmHg
* No hormone-altering contraceptive use (e.g., pill, patch, ring, injection)

Exclusion Criteria:

* Smoking
* Diabetes, cancer, or other metabolic disorders
* Cardiac or gastrointestinal problems
* Infectious disease
* Barium swallow or nuclear medicine scan in the previous 3 weeks
* Pregnant or breastfeeding
* Diagnosis of polycystic ovary syndrome
* Follow a vegan or vegetarian diet
* Not fully vaccinated against COVID19

Where this trial is running

Hamilton, Ontario

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 Healthy Nutritionglucose metabolismlipid metabolismsubstrate oxidation
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.