Functional hypothalamic amenorrhea and dietary intervention: A systematic review to guide further research in amenorrheic women without overt eating disorder.

Functional hypothalamic amenorrhea (FHA) is a multifactorial condition caused by psychological stress, energy deficit, weight loss, and excessive physical activity in the absence of adequate energy intake. Nutrition plays a key role in FHA treatment, with the primary intervention focused on correcting energy imbalance. Evidence regarding the exact amount of energy required to restore menses, the timeframe for recovery, and the optimal nutritional practices to support long-term recovery and optimize reproductive outcomes, remain limited. In this review, we aimed to assess if dietary intervention affects the nutritional status, food intake, nutrition knowledge, and hormonal milieu in women with FHA. We performed this review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, using the Population, Intervention, Control, Outcome, Study design criteria. A quality appraisal checklist for case series was used. The search included 4 databases and was restricted to English and Italian languages. Eleven articles were included. Five of these referred to the same population analyzed in 2 randomized controlled trials (RCTs); 3 nonrandomized controlled trials (NRCTs); and 1 nonrandomized uncontrolled trial, and 2 case series. Overall, the risk of bias was low for RCTs and moderate-to-high for NRCTs. Menstrual cycle can be restored in 1 to 12 months. One article indicated an additional 350 kcal/d energy intake to achieve this. However, the long-term impact of nutritional intervention alone remains unclear. Further research with a comprehensive, patient-centered approach is needed to confirm these findings and to clarify the possible role of nutritional counseling in FHA treatment.