The Effect of the Temperature of Plain or Sweetened Water on Body Composition in Rats

Introduction: Humans are known to adapt to external temperature variations by altering energy intake, expenditure, and body fat storage for insulation [1 , 2 ]. However, it is not clear whether the temperature of ingested water would induce such effects. Similarly, the involvement of the temperature of the ingested beverage has not been addressed in terms of body weight changes [3 ]. Objectives: This study was to investigate the effect of the ingestion of plain or sweetened water with varied temperatures on growth measures of rats. Methods: Approval was obtained from the Institutional Animal Care and Use Committee of the American University of Beirut. After a 1-week adaptation period, 5- to 6-week-old male Sprague-Dawley rats were randomly divided into their respective experimental groups, housed individually (22 ± 1°C, reverse light cycle 12:12 h dark/light, light off at 10:00 a.m.) with free access to food and beverage for 8 weeks. Experiment 1 (Plain Water): Two groups of rats (n = 9) consumed room-temperature [∼22°C] (NW) or cold [∼5°C] (CW) water. Experiment 2 (Sweetened Water): Four groups of rats were offered sweetened water for 12 h, followed by plain water; (1) 10% sucrose + cold temperature (CS, n = 7), (2) 10% sucrose + room temperature (NS, n = 8), (3) 0.05% acesulfame K + cold temperature (CA, n = 7), and 4) 0.05% acesulfame K + room temperature (NA, n = 8). Food and beverage intake, body weight, and body composition were monitored using NMR minispec (LF110 Body Composition Analyzer, Bruker, USA) and energy expenditure was calculated based on the equation developed by Ravussin et al. [4 ]. Significance was set at a p value