About this trial
Phenylalanine is an essential amino acid that must be obtained through food. Current adult phenylalanine recommendation is based on male-conducted studies and set the same for females. These recommendations may not be appropriate for females, as they do not take into consideration the hormonal changes over the menstrual cycle. The menstrual cycle is a rhythmic hormonal process split into two phases, with hormones regulating metabolism differently. The aim of this study is to find phenylalanine requirement for healthy, menstruating females. 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 females as well as in children.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
People with menstrual cycles
Between the ages of 20 to 35y
Regular menstrual cycle (21-35 day cycle) for the past 12 months
Body mass index (BMI) of between 18 and 28 kg/m2
Disqualifiers
People who are currently using hormonal birth control or any contraceptive that would affect sex hormones
People on hormone therapy
People with an abnormal menstrual cycle history
People with non-traditional dietary practices
Trial design
Single group
Treatments tested in this trial
Dietary Phenylalanine Intakes
Other interventionParticipants consume 8 hourly meals that contain the assigned test phenylalanine 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.
Treatment groups
Trial outcomes
Primary outcomes
Carbon 13 Oxidation
Urine and breath samples will be collected to measure the rate of L-\[1-13C\]-leucine oxidation.
Sponsors and contacts
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