For a long time, drinking water has been thought to help with weight loss.
In fact, 30–59% of US adults who try to lose weight increase their water intake (1, 2).
Many studies show that drinking more water may benefit weight loss and maintenance (3).
This article explains how drinking water can help you lose weight.
Drinking Water Can Make You Burn More Calories
Most of the studies listed below looked at the effect of drinking one, 0.5 liter (17 oz) serving of water.
Drinking water increases the amount of calories you burn, which is known as resting energy expenditure (4).
In adults, resting energy expenditure has been shown to increase by 24–30% within 10 minutes of drinking water. This lasts at least 60 minutes (5, 6).
Supporting this, one study of overweight and obese children found a 25% increase in resting energy expenditure after drinking cold water (7).
A study of overweight women examined the effects of increasing water intake to over 1 liter (34 oz) per day. They found that over a 12-month period, this resulted in an extra 2 kg (4.4 lbs) of weight loss (8).
Since these women didn’t make any lifestyle changes except to drink more water, these results are very impressive.
Additionally, both of these studies indicate that drinking 0.5 liters (17 oz) of water results in an extra 23 calories burned. On a yearly basis, that sums up to roughly 17,000 calories — or over 2 kg (4.4 lbs) of fat.
Several other studies have monitored overweight people who drank 1-1.5 liters (34–50 oz) of water daily for a few weeks. They found a significant reduction in weight, body mass index (BMI), waist circumference and body fat (8, 9, 10).
These results may be even more impressive when the water is cold. When you drink cold water, your body uses extra calories to warm the water up to body temperature.