[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"health-studies-list:{\"conditionNormalized\":\"energy-deficiency-due-to-short-term-fasting\",\"overallStatus\":[\"RECRUITING\",\"AVAILABLE\",\"NOT_YET_RECRUITING\"],\"orderBy\":\"LastUpdateSubmitDate:desc\",\"size\":25,\"offset\":0}":3,"health-study-condition:energy-deficiency-due-to-short-term-fasting":27},{"pageToken":4,"total":5,"offset":6,"count":5,"results":7},null,1,0,[8],{"id":9,"slug":10,"hasResults":11,"nctId":12,"briefTitle":13,"officialTitle":14,"acronym":4,"eligibilityCriteria":15,"healthyVolunteers":11,"sex":16,"minAge":17,"maxAge":18,"enrollmentInfo":19,"targetDuration":4,"studyType":22,"phases":23,"briefSummary":25,"conditions":26,"keywords":4,"overallStatus":29,"whyStopped":4,"lastUpdateSubmitDate":30,"lastUpdatePostDateStruct":31,"startDateStruct":34,"completionDateStruct":36,"leadSponsor":38,"locationsCount":5},"100642254","energy-deficiency-on-hormones-in-contraceptive-users-100642254",false,"NCT07651800","Energy Deficiency on Hormones in Contraceptive Users","Effects of a Modest Energy Deficit on Reproductive Hormones Across the Menstrual Cycle in Contraceptive Users","Inclusion Criteria:\n\n* Female, aged 18-35 years\n* Recreationally active (engaging in structured exercise between 8-15 hours per week)\n* BMI of 18.5-29.9 as a BMI below or above these cut points results in highly varied menstrual cycle lengths17\n* Not currently experiencing an eating disorder or disordered eating, or having a diagnosed eating disorder in the last 3 years\n* Non-pregnant or planning to become pregnant\n* Medically free from chronic diseases\n* Currently using one of the following contraceptive methods for ≥3 months:\n\nMonophasic oral contraceptive\n\n* Hormonal intrauterine device (H-IUD)\n* Copper intrauterine device\n* Weight stable (no weight change \\>5% body weight within the past 3 months)\n* Weight greater than or equal to 110 lbs\n* Not suffering from known gynecological disease (i.e., PCOS, endometriosis, etc.) that may influence menstrual cycle regularity\n* Willing and able to maintain current exercise habits throughout the study\n* Willing to follow study dietary guidance to achieve a \\~250 kcal\u002Fday energy deficit during Cycle 2\n\nExclusion Criteria:\n\n* Amenorrhea or oligomenorrhea\n* Perimenopausal or menopausal\n* Currently pregnant, planning pregnancy, or breastfeeding\n* Use of hormonal contraception other than monophasic oral contraceptives or hormonal IUD (implant, nuvaring, etc.)\n* Initiation or change of contraceptive method within the past 3 months\n* Diagnosis of polycystic ovary syndrome (PCOS), endometriosis, hypothalamic amenorrhea, or other known reproductive endocrine disorder\n* Current or history of eating disorder or clinically diagnosed disordered eating\n* Current participation in intentional weight loss or weight gain program\n* Use of medications known to affect metabolism or hormone levels (e.g., systemic corticosteroids, thyroid medications, insulin, GLP-1 agonists)\n* Known metabolic, cardiovascular, renal, hepatic, or endocrine disease\n* Musculoskeletal injury limiting exercise participation within the past 3 months\n* Smoking or nicotine use\n* Contraindications to DXA scanning (e.g., pregnancy, recent high-radiation diagnostic imaging exceeding institutional limits)\n* Inability or unwillingness to comply with study procedures","FEMALE","18 Years","35 Years",{"count":20,"type":21},30,"ESTIMATED","INTERVENTIONAL",[24],"NA","The purpose of the present study is to characterize the endocrine and metabolic responses to a modest, short-term energy deficiency (\\~250 kcal\u002Fday) across the menstrual cycle in recreationally active women using different contraceptive methods (oral contraceptive, hormonal IUD, and non-hormonal IUD). This study will leverage daily urinary hormone metabolite tracking and comprehensive metabolic assessments, providing foundational data addressing an important and previously unexamined interaction between energy availability and hormonal regulation in contraceptive users.",[27,28],"Energy Deficiency Due to Short-term Fasting","Hormonal Contraception","NOT_YET_RECRUITING","2026-06-10",{"date":32,"type":33},"2026-06-16","ACTUAL",{"date":35,"type":21},"2026-09",{"date":37,"type":21},"2027-12",{"name":39,"class":40},"University of Southern California","OTHER"]