Does Water Consumption Help You Lose Weight?
Does Drinking Water Help You Lose Weight?
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.
Fun Facts About Water:
- Humans can survive just 2-4 days without water
- Water comprises 60% of our body weight
Does Removing Water from Meals Affect Energy Intake?
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.
Does Substituting Water for a Caloric Beverage Affect Energy Intake?
No. Total energy intake was 14.9% higher from three studies when water was substituted for milk.
Water vs. Diet Beverages:
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.
Intervention Studies for Water and Weight Loss:
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.
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.”
- Daniels MC, Popkin BM.Impact of water intake on energy intake and weight status: a systematic review. Nutr Rev. 2010 Sep;68(9):505-21.