Weight Loss - Does Water Really Matter?

So, in the last quarter of 2018, I did a 2 L per day Whatsapp Water Drinking Challenge, and I asked participants to do it for 21 days (according to studies, or maybe fiction, it takes about 21 days of consistency to form or break a habit. However, some schools of thoughts have it that this is, as a matter of fact, a myth and that it takes even way longer, but that's not our focus today). I started by mentioning some wonderful benefits of water and why we would only be shortchanging ourselves by drinking less than the body really daily wants. I also posted daily reminders and motivations on my Whatsapp story, while also sharing my personal progress. One of the benefits I mentioned was that it helped in weight loss. But how?

How Can Drinking More Water Help You Lose Weight?
Many studies show that drinking more water may benefit weight loss and maintenance (1). In fact, studies have also 30–59% of US adults who try to lose weight increase their water intake. I will try to explain in this post how drinking water helps with weight loss, backing it up with a couple of  scientific research. Read on...

Drinking Water Can Make You Burn More Calories

Long-term weight management is directly proportional to calories absorbed from feeding. The importance of calorie monitoring just can't be overemphasised when you are trying to shed or maintain shed weight. Drinking water increases the amount of calories you burn, which is known as resting energy expenditure (2). In adults, resting energy expenditure has been shown to increase by 24–30% within 10 minutes of drinking water. This energy, in lay man's English, is the energy used to heat up water in the body. This is called thermogenesis and it lasts at least 60 minutes (3).

Most of the studies listed below looked at the effect of drinking one, 0.5 litre (17 oz) serving of water.

One is the study of overweight and obese children which found a 25% increase in resting energy expenditure after drinking cold water (4).

Another is a study of overweight women that examined the effects of increasing water intake to over 1 litre (34 oz) per day. They found that over a 12-month period, this resulted in an extra 2 kg (4.4 lb) of weight loss (5).

Additionally, both of these studies indicate that drinking 0.5 litre (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 lb) of fat. These results are very impressive, especially since all these women did was to drink more water, with no further lifestyle modifications in particular.

These results may be even more impressive when the water is colder. When you drink ice cold water, your body uses extra calories to warm the water up to body temperature.

Think about this.

If the colder the water means the more energy your body need to 'heat it up', and ultimately the more calories you are likely to burn. Wouldn't you rather chew ice blocks? 😄

Several other studies have monitored overweight people who drank 1-1.5 litres (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 (5, 6).

Drinking 0.5 litre (17 oz) of water may increase the amount of calories burned for at least an hour. Some studies show that this can lead to modest weight loss.

Drinking Water Before Meals Can Reduce Appetite Or Lead To Early Satiety

Some people claim that drinking water before a meal reduces appetite.

There actually seems to be some truth behind this, but almost exclusively in middle-aged and older adults.

Studies of older adults have shown that drinking water before each meal may increase weight loss by 2 kg (4.4 lbs) over a 12-week period (2, 7).

In one study, middle-aged overweight and obese participants who drank water before each meal lost 44% more weight, compared to a group that did not drink more water (2).

Another study also showed that drinking water before breakfast reduced the amount of calories consumed during the meal by 13% .

Although this may be very beneficial for middle-aged and older people, studies of younger individuals have not shown the same impressive reduction in calorie intake.

Drinking water before meals may reduce appetite in middle-aged and older individuals. This decreases calorie intake, leading to weight loss.

Drinking More Water is Linked to Reduced Calorie Intake and a Lower Risk of Weight Gain.

Since water is naturally calorie-free, it is generally linked with reduced calorie intake as against other beverages, which are often high in calories and sugar.

Observational studies have shown that people who drink mostly water have up to a 9% (or 200 calories) lower calorie intake, on average (8).

Drinking water may also help prevent long-term weight gain. In general, the average person gains about 1.45 kg (3.2 lb) every 4 years (9).

This amount may be reduced by:

1 more cup: Increasing your daily water consumption by 1 cup may reduce this weight gain by 0.13 kg (0.23 lb).

Water over beverage: Substituting a serving of a sugar-sweetened beverage with 1 cup of water may reduce the 4-year weight gain by 0.5 kg (1.1 lb).

It is especially important to encourage children to drink water, as it can help prevent them from becoming overweight or obese.

How Much Water Should You Drink?

I am sure you must have heard about the 8 * 8 rule, which states that you should drink eight, 8-ounce glass of water per day, which is an equivalent of 2 litres. This was also what gave birth to my 21-day challenge. However, you should bear in mind that this rule is just a guideline to what is required and is not hard and fast. An individual's water need will depend on their water loss, and as such someone with diuresis or excessive sweating will more likely have more need for water than just eight 8-oz glasses in a day. As a matter of fact, a rule of thumb is that you should drink water whenever you are thirsty, and drink enough to quench your thirst.

Keep in mind that you also get water from many foods and beverages, such as coffee, tea, meat, fish, milk, and especially fruits and vegetables.

However since we are on the subject of water as it relates to weight loss management, the studies referenced above have shown that about 1-2 L per day of water would be sufficient in losing weight. 

But you know, as much as water is beneficial in weight loss, it is just one piece of the puzzle, you're going to have to do a lot more than just drink water if you need to lose a significant amount of weight.