Randomised controlled trial of the effects of increased energy intake on menstrual recovery in exercising women with menstrual disturbances: the ‘REFUEL’ study

• Published in: Human reproduction (Oxford) 2021-07, Vol.36 (8), p.2285-2297
• Main Authors: De Souza, Mary Jane, Mallinson, Rebecca J, Strock, Nicole C A, Koltun, Kristen J, Olmsted, Marion P, Ricker, Emily A, Scheid, Jennifer L, Allaway, Heather C, Mallinson, Daniel J, Kuruppumullage Don, Prabhani, Williams, Nancy I
• Format: Article
• Language: English
• Subjects: Original
• ISSN: 0268-1161; 1460-2350
• DOI: 10.1093/humrep/deab149

STUDY QUESTIONDoes increased daily energy intake lead to menstrual recovery in exercising women with oligomenorrhoea (Oligo) or amenorrhoea (Amen)? SUMMARY ANSWERA modest increase in daily energy intake (330 ± 65 kcal/day; 18 ± 4%) is sufficient to induce menstrual recovery in exercising women with Oligo/Amen. WHAT IS KNOWN ALREADYOptimal energy availability is critical for normal reproductive function, but the magnitude of increased energy intake necessary for menstrual recovery in exercising women, along with the associated metabolic changes, is not known. STUDY DESIGN, SIZE, DURATIONThe REFUEL study (trial # NCT00392873) is the first randomised controlled trial to assess the effectiveness of 12 months of increased energy intake on menstrual function in 76 exercising women with menstrual disturbances. Participants were randomised (block method) to increase energy intake 20-40% above baseline energy needs (Oligo/Amen + Cal, n = 40) or maintain energy intake (Oligo/Amen Control, n = 36). The study was performed from 2006 to 2014. PARTICIPANTS/MATERIALS, SETTING, METHODSParticipants were Amen and Oligo exercising women (age = 21.0 ± 0.3 years, BMI = 20.8 ± 0.2 kg/m2, body fat = 24.7 ± 0.6%) recruited from two universities. Detailed assessment of menstrual function was performed using logs and measures of daily urinary ovarian steroids. Body composition and metabolic outcomes were assessed every 3 months. MAIN RESULTS AND THE ROLE OF CHANCEUsing an intent-to-treat analysis, the Oligo/Amen + Cal group was more likely to experience menses during the intervention than the Oligo/Amen Control group (P = 0.002; hazard ratio [CI] = 1.91 [1.27, 2.89]). In the intent-to-treat analysis, the Oligo/Amen + Cal group demonstrated a greater increase in energy intake, body weight, percent body fat and total triiodothyronine (TT3) compared to the Oligo/Amen Control group (P