Increasing the amount of water you drink has been proven to help with weight loss, as well as preventing weight gain. (1)
The idea isn’t new; between 30% and 59% of people on weight loss programs say they increase water intake as part of their plan. (2)
Information from most studies detailed below based conclusions on subjects drinking 17 ounces of water, a considerably larger amount than what might normally be considered one serving.
- Drinking More Water Raises the Amount of Calories Burned
The body’s resting energy expenditure level determines how many calories are burned while you’re not engaged in motion.
Drinking water bumped up resting energy expenditure in participants of one study by 24% to 30% within ten minutes. The effects lasted a full hour, and longer in some cases. (3)
Water temperature may play a role as well. When obese and overweight children drank chilled water, resting energy expenditure increased by 25%. (4)
Another study evaluated the effects on overweight women from drinking 34 ounces of water daily over a year’s time. Participants made no other lifestyle modifications, yet they dropped an average of nearly 5 pounds during the study. (5)
Research analysts estimated these women burned an extra 17,000 calories in 12 months.
Other studies verify that drinking between 1 and 1.5 liters of water daily results in significant changes for overweight people in just a few weeks. Participants in a number of trials lost weight as well as reducing body mass index (BMI), total body fat, and waist circumference. (6, 7)
These results are impressive, and the potential for more loss exists when drinking cold water, since the body uses energy to warm cold fluids introduced into the stomach.
- Drinking Water Before a Meal Can Make You Eat Fewer Calories
This isn’t a new idea either, but studies show drinking more water is most effective at reducing calorie consumption for adults who are middle-aged or older. (8)
Data from a clinical trial indicated older adults who drank water before each meal lost about 4 more pounds over three months than those who didn’t make a point of drinking more than they usually did. (9)
Drinking water before breakfast cut the number of calories consumed by middle-aged participants in another study to the tune of 13%. (10)
It’s not clear why younger people don’t experience the same effects.
- A General Link Exists Between Higher Water Intake and Lower Calorie Consumption
When you drink more water, you’re less likely to be drinking fluids with calories, like fruit juice, soft drinks, sweetened coffee or tea.
Drinking plenty of water may also help prevent long-term weight gain.
It’s common for people to gain just under a pound each year as they age; some might only gain 7 or 8 pounds in a decade, while others might find themselves ten pounds heavier, or even more. (13)
Increasing daily water intake by a single cup could cut back weight gain to less than a quarter of a pound annually.
Trading one sugar-sweetened beverage each day for the equivalent amount of water can also make a positive difference in the amount of weight gained over the years.
Reminding children to drink water could play a role in preventing obesity.
One recent study conducted in a school setting educated second- and third-graders about the importance of drinking water; more water fountains were installed as part of the program.
Control groups in other schools were not provided any instruction on the health benefits of drinking water, and no changes were made to existing water supplies.
In a single year, the children attending schools where more water consumption was encouraged dropped the risk of obesity by 31%. (14)
How to Make Sure You’re Drinking Enough Water
Most of us have heard the official recommendation to drink eight 8-ounce glasses of water daily, which amounts to about two liters.
This random amount doesn’t account for individual needs and requirements, which differ depending on size, physical activity and other factors. (15)
Age is an important variable; older people need more water, and mothers who are breastfeeding require a significantly larger amount of water to make milk. (16)
Anyone who exercises enough to work up a sweat and sustain it for any length of time will need to replace lost fluids with more liquid.
We get water from many sources, including beverages like coffee and tea. Fruits and vegetables also add water to the system, and small amounts can even be obtained through foods like fish, milk and meat.
It’s important to pay attention when you feel thirsty; drink enough water to quench your thirst.
- Difficulty concentrating, or other cognitive issues, including memory problems
- Frequent headaches that can’t be attributed to other causes
- Constant hunger, especially for sweet foods
- Mood swings
- Feeling fatigued for no apparent reason
- Dry skin
- Bad breath
- Muscle cramps
To support weight loss, try to establish the habit of drinking between one and two liters of water daily. This amounts to between 34 and 67 ounces, or four to eight 8-ounce glasses.
Special situations will call for more water, as mentioned above.
Just for the record, it’s possible to overdo it. Excess water causes the sodium (salt) content of blood to drop too low, which can result in death. The medical term for this is hyponatremia, also called water intoxication. (21)
Most people who died of water intoxication were participating in water drinking contests, and consumed gallons of water in a short period of time; some ingested too much water during and after intense exercise. (22)
Every cell in the body needs water to function properly, and providing adequate amounts every day is vital. Substituting water for other beverages is completely safe, and has health benefits beyond supporting weight loss.
Summary: Drink water before meals to help reduce appetite and rev up your metabolism. When combined with other strategies like choosing healthy foods and exercising more, water can be an integral component of your successful weight-loss plan.