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Updated: Oct 9, 2025

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Published on: February 10, 2023
Comparing thirst and spot urine concentrations in humans of differing body sizes: An observational study
J D Adams1, Ashton E Barlow1, Donya Z Farzam1
1Department of Health and Human Performance, College of Charleston, Charleston, SC, United States of America.
Abstract:
Elevated body mass index (BMI) has been associated with elevated urine osmolality (UOsm), despite having higher total water intake, but it is unclear if overweight/obese individuals have reduced thirst. In this observational study, we found that overweight/obese individuals had higher UOsm compared to normal-weight individuals (749 ± 37 vs. 624 ± 35 mmol•kg-1; P < 0.01) while possessing similar thirst ratings (56.4 ± 3 vs. 51.6 ± 3 mm; P = 0.3). In this observational study, overweight/obese individuals possessed more concentrated urine in the absence of higher thirst perception.
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