British Journal of Nutrition

  • British Journal of Nutrition / Volume 109 / Issue 02 / January 2013, pp 313-321
  • Copyright © The Authors 2012. The online version of this article is published within an Open Access environment subject to the conditions of the Creative Commons Attribution-NonCommercial-ShareAlike licence <>. The written permission of Cambridge University Press must be obtained for commercial re-use.
  • DOI: (About DOI), Published online: 13 April 2012

Full Papers

Human and Clinical Nutrition

Influence of progressive fluid restriction on mood and physiological markers of dehydration in women

Nathalie Prossa1, Agnès Demazièresa1, Nicolas Girarda1, Romain Barnouina1, Francine Santoroa1, Emmanuel Chevillottea2, Alexis Kleina2 and Laurent Le Bellegoa2 c1

a1 Forenap- 27 rue du 4ème RSM, 68250 Rouffach, France

a2 Danone Research, RD 128, 91767 Palaiseau, France


The present study evaluated, using a well-controlled dehydration protocol, the effects of 24 h fluid deprivation (FD) on selected mood and physiological parameters. In the present cross-over study, twenty healthy women (age 25 (se 0·78) years) participated in two randomised sessions: FD-induced dehydration v. a fully hydrated control condition. In the FD period, the last water intake was between 18.00 and 19.00 hours and no beverages were allowed until 18.00 hours on the next day (23–24 h). Water intake was only permitted at fixed periods during the control condition. Physiological parameters in the urine, blood and saliva (osmolality) as well as mood and sensations (headache and thirst) were compared across the experimental conditions. Safety was monitored throughout the study. The FD protocol was effective as indicated by a significant reduction in urine output. No clinical abnormalities of biological parameters or vital signs were observed, although heart rate was increased by FD. Increased urine specific gravity, darker urine colour and increased thirst were early markers of dehydration. Interestingly, dehydration also induced a significant increase in saliva osmolality at the end of the 24 h FD period but plasma osmolality remained unchanged. The significant effects of FD on mood included decreased alertness and increased sleepiness, fatigue and confusion. The most consistent effects of mild dehydration on mood are on sleep/wake parameters. Urine specific gravity appears to be the best physiological measure of hydration status in subjects with a normal level of activity; saliva osmolality is another reliable and non-invasive method for assessing hydration status.

(Received October 05 2011)

(Revised February 17 2012)

(Accepted February 17 2012)

(Online publication April 13 2012)

Key Words:

  • Dehydration;
  • Mood;
  • Saliva;
  • Urine


c1 Corresponding author: L. L. Bellego, fax +33 1 69 35 76 93, email


  Abbreviations: AE, adverse events; FD, fluid deprivation; POMS, Profile of Mood States; Ucol, urine colour; Uvol, urine volume; USG, urine specific gravity; VAS, visual analogue scale