---
title: Does being underweight affect sleep differently across the cycle?
description: Underweight and normal weight women had similar sleep overall. Underweight women woke more during the first part of their cycle and had lower sleep hormones d
url: https://niyora.com/research/papers/sleep-characteristics-in-underweight-young-females-across-their-menstrual-cycles-2025/
---

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- Does being underweight affect sleep differently across the cycle?

Survey study, 2025

# Does being underweight affect sleep differently across the cycle?

Underweight and normal weight women had similar sleep overall. Underweight women woke more during the first part of their cycle and had lower sleep hormones during the second part.

 Early or limited evidence

28 female university students aged 18-24 in Japan (10 underweight, 18 normal weight)

## What they did

Researchers followed 28 female university students aged 18-24 in Japan (10 underweight and 18 normal weight) across their menstrual cycles. They measured sleep using daily questionnaires, sleep sensors under the mattress, and a sleep hormone measured in urine.

## What they found

Underweight and control groups showed no significant differences in sleep patterns across cycle phases on questionnaires or sensors. Underweight women experienced more difficulty staying asleep during the follicular phase. A higher percentage of underweight women (7 of 10) had decreased sleep hormone levels during the luteal phase compared to the control group (3 of 13).

## What it means for you

Being underweight may affect sleep quality, particularly the ability to stay asleep and possibly hormone levels. This is a very small preliminary study from Japan. The main limit is only 28 women were studied, so results may change with larger numbers.

28

women studied

10

were underweight

7 of 10

underweight had low hormone levels in luteal phase

## About the study

Original title Sleep characteristics in underweight young females across their menstrual cycles: A sleep-monitoring survey study with preliminary results Authors Kayaba M, Yajima K, Nogami M et al. Journal Journal of sleep research Year 2025 Study design Survey study Participants 18 What was tested None Read the paper [doi.org/10.1111/jsr.14254](https://doi.org/10.1111/jsr.14254)

## Topics

[Sleep and insomnia](https://niyora.com/research/topics/symptom-sleep/)[Students and academic performance](https://niyora.com/research/topics/life-area-education/)

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