Water drinking induces thermogenesis through osmosensitive mechanisms.
BACKGROUND
Recently, we showed that drinking 500 ml water induces thermogenesis in normal-weight men and women.


OBJECTIVE
We now repeated these studies in a randomized, controlled, crossover trial in overweight or obese otherwise healthy subjects (eight men and eight women), comparing also the effects of 500 ml isoosmotic saline or 50 ml water.


RESULTS
Only 500 ml water increased energy expenditure by 24% over the course of 60 min after ingestion, whereas isoosmotic saline and 50 ml water had no effect. Heart rate and blood pressure did not change in these young, healthy subjects.


CONCLUSIONS
Our data exclude volume-related effects or gastric distension as the mediator of the thermogenic response to water drinking. Instead, we hypothesize the existence of a portal osmoreceptor, most likely an ion channel.
Boschmann
Michael
M
Franz Volhard Clinical Research Center and Helios-Klinikum-Berlin, Charité Campus Buch, Universitary Medicine Berlin, Wiltbergstrasse 50, Hs. 129, D-13125 Berlin, Germany.
Steiniger
Jochen
J
Franke
Gabriele
G
Birkenfeld
Andreas L
AL
Luft
Friedrich C
FC
Jordan
Jens
J
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D018592:Cross-Over Studies; D004326:Drinking / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D009765:Obesity / Q000503:physiopathology; D012965:Sodium Chloride / Q000494:pharmacology; D022722:Thermogenesis / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology*
D012965:Sodium Chloride