Thermogenic effect of drinking water
Imagine increasing your energy expenditure by 24% simply by drinking water!
Water Drinking Induces Thermogenesis through Osmosensitive Mechanisms
Michael Boschmann, Jochen Steiniger, Gabriele Franke, Andreas L. Birkenfeld, Friedrich C. Luft, and Jens Jordan*
Franz-Volhard Clinical Research Center and Helios-Klinikum-Berlin, Charité Campus Buch, Universitary Medicine Berlin, Germany
* To whom correspondence should be addressed. E-mail: firstname.lastname@example.org.
Context. 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 (8 men and 8 women) comparing also the effects of 500 ml iso-osmotic saline or 50 ml water.
Results. Only 500 ml water increased energy expenditure by 24% over the course of 60 minutes after ingestion, while iso-osmotic 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.
That one below was the first that I read several years ago.
Boschmann M,Steiniger J, Hille U, et al. Water-induced thermogenesis. J Clin Endocrinol Metab. 2003;88(12):6015-9.
Drinking lots of water is commonly espoused in weight loss regimens and is regarded as healthy; however, few systematic studies address this notion. In 14 healthy, normal-weight subjects (seven men and seven women), we assessed the effect of drinking 500 ml of water on energy expenditure and substrate oxidation rates by using whole-room indirect calorimetry. The effect of water drinking on adipose tissue metabolism was assessed with the microdialysis technique. Drinking 500 ml of water increased metabolic rate by 30%. The increase occurred within 10 min and reached a maximum after 30-40 min. The total thermogenic response was about 100 kJ. About 40% of the thermogenic effect originated from warming the water from 22 to 37 C. In men, lipids mainly fueled the increase in metabolic rate. In contrast, in women carbohydrates were mainly used as the energy source. The increase in energy expenditure with water was diminished with systemic beta-adrenoreceptor blockade. Thus, drinking 2 liters of water per day would augment energy expenditure by approximately 400 kJ. Therefore, the thermogenic effect of water should be considered when estimating energy expenditure, particularly during weight loss programs.
On the other hand, there is a study that says H20 does nothing for burning calories:
Brown CM, Dulloo AG, Montani JP. Water-induced thermogenesis reconsidered: the effects of osmolality and water temperature on energy expenditure after drinking. J Clin Endocrinol Metab. 2006;91(9):3598-602.
CONTEXT: A recent study reported that drinking 500 ml of water causes a 30% increase in metabolic rate. If verified, this previously unrecognized thermogenic property of water would have important implications for weight-loss programs. However, the concept of a thermogenic effect of water is controversial because other studies have found that water drinking does not increase energy expenditure. OBJECTIVE: The objective of the study was to test whether water drinking has a thermogenic effect in humans and, furthermore, determine whether the response is influenced by osmolality or by water temperature. DESIGN: This was a randomized, crossover design. SETTING: The study was conducted at a university physiology laboratory. PARTICIPANTS: Participants included healthy young volunteer subjects. INTERVENTION: Intervention included drinking 7.5 ml/kg body weight (approximately 518 ml) of distilled water or 0.9% saline or 7% sucrose solution (positive control) on different days. In a subgroup of subjects, responses to cold water (3 C) were tested. MAIN OUTCOME MEASURE: Resting energy expenditure, assessed by indirect calorimetry for 30 min before and 90 min after the drinks, was measured. RESULTS: Energy expenditure did not increase after drinking either distilled water (P = 0.34) or 0.9% saline (P = 0.33). Drinking the 7% sucrose solution significantly increased energy expenditure (P < 0.0001). Drinking water that had been cooled to 3 C caused a small increase in energy expenditure of 4.5% over 60 min (P < 0.01). CONCLUSIONS: Drinking distilled water at room temperature did not increase energy expenditure. Cooling the water before drinking only stimulated a small thermogenic response, well below the theoretical energy cost of warming the water to body temperature. These results cast doubt on water as a thermogenic agent for the management of obesity.
"The medals don't mean anything and the glory doesn't last. It's all about your happiness. The rewards are going to come, but my happiness is just loving the sport and having fun performing" ~ Jackie Joyner Kersee.