An interventional study of Dietary Leucine Intakes in Menstrual Cycle, sponsored by University of British Columbia. Completed at 1 site in Canada. Open to female participants aged 20 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-02-12.
Sponsored by University of British Columbia · Not applicable, Interventional, and Basic science
The existing guidelines for dietary amino acid intake for women are set the same as those established for men. These recommendations might not be appropriate for women, as they do not take into consideration important differences between male and female physiology, like the menstrual cycle. This study aims to determine the leucine requirements during the phases of the menstrual cycle. Leucine is an essential amino acid (cannot be made naturally in the body) and is necessary for protein synthesis, and other important cellular functions. Consuming an adequate amount daily is crucial for maintaining overall health. An innovative, non-invasive technique utilizing pre-determined diets, safe stable isotopes, and a simple breath collection method will be used. Previous work done by Elango Lab investigators has applied this method to investigate other amino acids in pregnant, non-pregnant, and lactating women.
The objective of the study is to determine leucine requirements using the indicator amino acid oxidation method during the follicular phase and the luteal phase of the menstrual cycle in healthy women (between the ages of 20-35 y).In comprehending protein needs and achieving protein targets, it is imperative to establish individual amino acid requirements. This clinical study aims to determine the dietary requirements of leucine for women, helping build a strong foundation for setting dietary guidelines for women. The existing values, derived from guidelines designed for men, overlook the crucial impact of the menstrual cycle on energy and dietary intake. Relying on amino acid requirements derived from studies in men for women significantly heightens the risk of potential harm. It is crucial to identify the distinct amino acid requirements for women and grasp how these needs are affected by various phases of the menstrual cycle. A minimum of 15 healthy women (20-35 y) will be recruited and studied at two menstrual phases over a range of test leucine intakes (10, 20, 30, 40, 55, 70, and 85 mg/kg/day). Women will be invited to participate in up to 7 study days/phase, and randomized to a different intake at each study day. Participants' eligibility will be assessed during a pre-study day. The goal is to study a minimum of 7 women at each intake, for a total of 49 study days in each stage.
University of British Columbia is the lead sponsor of 1,309 studies on the registry; 253 are open to participants now.
Of its 6 completed or terminated interventional studies of FDA-regulated products, 1 (17%) have results posted.
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Exclusion Criteria:
Randomly assigned one of 7 test leucine intakes that range from deficient to excess (10mg/kg/d to 85mg/kg/d). Participants may complete up to 7 study days in each menstrual phase, at different randomly assigned intakes.
Other: Dietary Leucine Intakes
Participants consume 8 hourly meals that contain the assigned test leucine intake. Each meal will provide one-twelfth of the participants' daily energy requirements as estimated by 1.5 x Resting Energy Expenditure (REE) and adequate protein at 1.0 g.kg.d, to maintain a metabolic steady state. The meals are in the form of a crystalline amino acid protein shake, and protein-free cookies.
Carbon 13 Oxidation
Urine and breath samples will be collected to measure the rate of L-\[1-13C\]phenylalanine oxidation.
Time frame: 8 hours
This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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University of British Columbia