Water. Yes, conventional wisdom often suggests that drinking more water can help you lose weight. One of the weight loss tips at my blog by a guest author was to drink cold water to speed up metabolism. Of course, water like anything else when consumed in excess can be dangerous. As I learned early on in a pharmacology class many years ago, the dose makes the poison.
One of the first patients that I saw on a psychiatric ward was admitted for delirium. What was the cause? He had a severe hyponatremia (low sodium levels) secondary to consuming an excessive amount of water. From what I can recall, the patient had attempted to “purify his system” by drinking 4 x 5 gallon jugs of mineral water. I’m not sure how far into that attempt he managed to get, but the outcome was the same.
Researchers at the University of North Carolina at Chapel Hill published a recent systematic review on the impact of water intake on energy intake and weight status. Specifically, they included all relevant clinical trials, epidemiologic studies, and intervention studies which were available in the English language.
Yes. From the current literature that the study authors cite, studies typically find a reduction in calories when water is added to the diet. Conversely, meal energy increased by 8.7% when water was removed.
No. Total energy intake was 14.9% higher from three studies when water was substituted for milk.
The study results were generally inconclusive, but one study found total energy intake increased by 13.8% when women drank diet lemonade on day 2 instead of water.
The researchers only located four studies which explored drinking water as a weight loss intervention. Two of the studies were of older adults while the other two included school-age children.
[box type=”important”]When combined with weight-loss training in older adults, the group assigned to drink water before meals lost 5.4 kg compared to 3.3 in the group that did not drink water before meals after 12 weeks. (-5.4 +/- 0.6 kg versus -3.3 +/- 0.5 kg,P = 0.01). [/box]
In a study involving German children, those schools that had educational and environmental interventions to increase water intake had a lower adjusted risk of overweight children compared to schools that did not institute this intervention (OR, 0.69; 95% CI, 0.48–0.98). Overall, the students at the schools with the intervention drank 1.1 glasses of water per day more than at the other schools.
The study authors noted significant gaps in the literature and the need for additional studies.
From the study authors:
“These findings from clinical trials, along with those from epidemiologic and intervention studies, suggest water has a potentially important role to play in reducing energy intake, and consequently in obesity prevention.”
Imagine that! Look no further than free drinking water to help reduce energy intake and prevent obesity. If there was a diet product that worked as well as plain old water, imagine how expensive it would be?