Does Drinking Water Help You Lose Weight?

The world’s elixir of life is no magic potion – in fact, you may (or should!) have already had a glass or two of it today. Yes, water is something we should all be drinking plenty of, though most of us don’t get nearly enough of it. And now that more and more research is finding that there is a strong link between dehydration and obesity, there’s more than good reason to start drinking up!¹

Most Americans drink far less water than they should. According to USDA data, the average American consumes under 4 glasses a day – about half of the ideal amount.²

Looking further into this, the lack of water in your diet could also be slowing down your efforts to lose weight, even if you’ve already significantly improved your diet and increased your physical activity. Those already on a weight-loss plan may first want to take stock of your water intake – it could play a decisive part in your success.

Water And Your Weight: The Connection

While we all know that the body needs to be adequately hydrated to function properly, the link between water and your weight may not be as obvious. One group of researchers studied data from the National Health and Nutrition Examination Survey, which examined adults between 18 and 64 years old, for the years between 2009 and 2012. They found that inadequate hydration was significantly associated with obesity and a higher BMI.³ The researchers found the results to be promising enough to suggest further study on the connection between water intake and weight management.

Another study assessed the impact of increased water consumption on preventing children from becoming overweight. The risk of being overweight went down by as much as 31 percent in schools where daily water intake went up by 1.1 glasses.⁴

Drink More Water, Lose More Weight

Research has found that increased water consumption can help those trying to lose weight, though this has not been directly proven for the broader population.⁵ One particular study of overweight women on a diet found that drinking more water was linked to greater weight loss – including overall fat loss – independent of both activity levels and diet.⁶

Decrease Your Overall Calorie Intake

Drinking water before you eat could also help you cut down your caloric intake. One study of middle-aged and older adults tested the impact of water consumption alongside a hypocaloric or reduced calorie diet. Drinking 500 ml of water before the main meal of the day resulted in greater weight loss as a result of eating fewer calories. This means, filling up with a little water before each meal could potentially aid in weight loss.⁷

Trade In Sugary Beverages For A Refreshing Glass Of Water

Quenching your thirst with water means you’re also less likely to reach for a sugary or high-calorie beverage. This simple switch to water is potentially beneficial for your body weight.⁸ One particular study confirmed this theory. Subjects aged 21 to 59 years old saw their caloric beverage intake drop by 20 ml for every 100 ml increase of plain water consumption.⁹

Get The Most Out Of Your Workout

Not drinking adequate water can negatively impact your exercise regimen as well. You need to ensure you stay hydrated during any workout. While most people are well-hydrated when they begin their exercise, they tend to forget to keep drinking during their workout. A combination of heat stress and the physical exercise itself can cause electrolyte and fluid imbalances. If water and electrolytes are not replaced during the workout, you likely won’t see optimal results – dehydration can negate the calorie-burning effects of high-aerobic fitness.¹⁰

Can Water Boost Your Metabolism? Mixed Results From Studies

Water consumption could even bump up your metabolic rate. A small study found that drinking half a liter of water resulted in a 30 percent rise in metabolic rate. This hike in metabolism occurred as early as 10 minutes after the water was consumed, peaking at 30 to 40 minutes post-consumption. Male bodies used lipids while females burnt through carbs to fuel the rise in metabolism. In this instance, the researchers said the revving up of the internal engines happens due to the metabolic action needed to raise water temperature from about 22 degrees celsius (room temperature) to 37 degrees (your body temperature).¹¹

However, later research found that this thermogenesis-linked rise of metabolism may not be all it’s cracked up to be. Researchers found that energy expenditure of test subjects did not go up when they drank plain distilled water or plain saline water at room temperature. When the water was cooled to 3 degrees celsius it did cause a small rise in energy expenditure – but this was just 4.5 percent over an hour, nowhere near the impressive 30 percent of the previous study.¹² This means, that while it is important to keep hydrated to run your body efficiently, it may not necessarily boost your metabolism to the degree some have claimed.

So, How Much Water Should You Drink?

While some studies do peg it at 1–2 liters daily, there is no magic number for everyone.¹³ Water consumption varies depending on myriad things, including your activity levels, metabolism, body weight, gender, and weather or environmental conditions where you live and work.¹⁴ However, there are some broad guidelines. For instance, the National Health Service recommends consuming 6 to 8 glasses (or about 1.2 liters) of water a day to prevent dehydration and enable your body to function optimally.¹⁵ For those who have a strenuous exercise routine, more water and electrolytes will need to be consumed based on the intensity and duration of the workout.

Another way to check your hydration levels is to simply look at the color of your urine. Experts quoted in a Time article suggest that light-colored urine is an indication that you’re probably drinking enough water. The darker your urine, the more water you should consume.¹⁶