Water for Weight Loss: The importance of Water in Your Diet Plan

by Marixie Ann Obsioma, MT, undergrad MD on June 30, 2021
Last updated on July 10, 2021

Drinking enough water regularly offers many benefits that are often overlooked. Although there is no one simple way to achieve a healthy lifestyle, your eating plans won’t be successful without a nice, refreshing water included in your diet.

Water for Weight Loss: The importance of Water in Your Diet Plan

Some Facts About Water and the Human Body

Water is a combination of elements that makes up the fluids in our bodies – hydrogen and oxygen. Water makes up over two-thirds of one’s weight and 60 percent of the body, which is why humans can potentially die within a few days without it (1)(2).

Every cell and organ in the body needs water in order to function. Plus, water serves other important functions, such as lubrication (in the form of saliva and other fluids surrounding the joints), in body temperature regulation (through perspiration). Also, water helps in the prevention and relief from constipation by helping food to move through the intestines (1).

Sources of Water

Apart from taking it in through drinking water, water can also be sourced from the foods you eat – like fish (3) – as some water can be produced from the process of metabolism. Other sources of water include liquid foods like soup, and beverages like coffee, milk, soda, tea, and juices. Note, however, that alcohol is a diuretic, so it is not a source of water. Instead, alcohol causes the body to release water (1).

Several health authorities recommend drinking around 8 glasses of 8-oz water a day (3). Moreover, the Dietary Reference Intake for water comes between 2.7 to 3.7 liters (or 91 to 125 fluid ounces) each day for adults (1).

However, it is important to know that every individual is different; thus, the amount of water one should get depends on factors like weight, age, activity level, and possible medical conditions. That said, there is no specific recommendation for how much water one should take (1) and water requirements would solely depend on the individual (3).

However, people who exercise regularly and sweat a lot may be required to take in more fluids than those who are not (3). When it comes to your diet plan, always choose water over sweetened drinks, as these beverages can lead you to take in more calories than you should (1).

The general rule is that you should drink enough water when thirsty, and when you do so, make sure that the amount is enough to quench your thirst and stay hydrated (1)(3). Based on researches, drinking at least 1 to 2 liters of water can help with weight loss (3).

How Can Water Help You Lose Weight?

A popular notion is that all of us can live longer without food than without water. Basically, water is necessary for our survival – especially for body functions and processes that include digestion and elimination (4).

Moreover, there are many studies that support the idea that drinking water aids in weight loss. For one, staying hydrated aids in many factors concerning weight loss, like muscle function (5).

There are many studies that show a positive correlation between drinking more water and weight loss (5). If you’re wondering why it’s important to incorporate water in your diet plan, below are the several benefits of water for weight loss.

1. Water is a Natural Appetite Suppressant

Water is a great weight loss aid because it helps you consume less food. According to a registered dietician at the University of Texas Medical School in Houston, Donna Logan, RD, drinking water helps in weight loss as it keeps you hydrated without the unnecessary calories and feel full sooner (4).

As water takes up more space in your stomach, the organ feels full and signals the brain to stop taking in food (5). Thus, drinking water is said to promote satiation, since it quickly passes through your system, stretching your stomach. According to an internist and board-certified physician and nutrition specialist, Melina Jampolis, this sends a message to the brain that your body is full. She explains that thirst triggered by mild dehydration is often mistaken as hunger by your brain (6).

However, there may be times when a person may perceive hunger for the thirst that they are actually feeling. So, to avoid unnecessary eating, you can drink a glass of water before taking your meal (5).

2. Warns Aids in Burning Calories

There are researches that prove that drinking water helps you burn calories. For instance, a 2014 study revealed that people who drank 500 mL of cold and room-temperature water had an increase in energy use and burned around 2 to 3 percent more calories after 90 minutes. Interestingly, they also found that water can increase the number of calories burned while resting – also known as the body’s resting energy expenditure (5).

In addition, drinking cold water can further improve water’s calorie-burning benefits; as the body can burn calories by heating up the water during digestion (5). Instead of adding calories in your body, water helps you avoid unnecessary food calories from snacks or extra servings and eliminate wastes from the body (4), which leads me to my next point…

3. Water is Helps in Removing Waste

The body removes waste in the form of urine (which is largely made up of water) or feces (which water keeps soft). Thus, the more hydrated you are, the easier it is for your system to move things along your intestinal tract and keep yourself from constipation and bloating. Otherwise, your kidney retains fluid and your body cannot correctly remove waste – leading to lumpy stools and constipation (5)(2).

Water also helps you to recover from digestive concerns like indigestion and diarrhea, and it promotes kidney function by helping your kidneys filter toxins and waste while keeping essential nutrients and electrolytes, which is especially important in fat metabolism and weight loss. It also flushes bacteria from your urinary tract and prevents kidney stones (4)(5)(2).

When waste builds up in your body, you can feel swollen, tired, and bloated. More specifically, bloating can result in additional inches in your waist. Thus, staying hydrated helps you retain waste that can add some pounds (5)(2).

4. Water is Necessary to Burn Fat

A 2016 mini-review of animal studies published in Frontiers in Nutrition points out that increasing your water intake may help your body burn fat for energy – a process known as lipolysis (5)(2). They further note that, possibly due to hormonal changes, mild dehydration decreases lipolysis. Plus, they also posed the theory in animal studies that water expands cell volume, which can potentially play a role in fat metabolism. However, it still needs to be proven in human studies (2).

Without water, our body cannot properly metabolize stored fat or carbohydrates. In lined with this, lipolysis begins with the process of hydrolysis, which happens when water molecules interact with fats to produce fatty acids and glycerol. Thus, drinking water is needed to burn fat from snacks and beverages, as well as stored fat (5).

5. Drinking Water Reduces Liquid Calorie Intake

Drinking sweetened beverages like coffee, sweet tea, juice or soda, makes it easy for you to accumulate liquid calories. Unfortunately, a lot of people also ignore their calorie intake in alcoholic beverages and sports drinks (5). Water contains no calories, which is why it is a perfect alternative for high-calorie beverages like juice, soda, or coffee. Water lessens your liquid overall calorie intake (2).

Moreover, it is found that replacing some high-calorie drinks every day for water or other non-calorie drinks like herbal tea can have long-term weight loss benefits. Results from a large-scale study reveals individuals who replaced a serving of a sugar-sweetened beverage with water or a low-calorie drink each day for a span of 4 years gained 0.49 kg less weight than those who did not (5).

Furthermore, the researchers found that adults who replaced a serving of fruit juice for the same alternatives gained 0.35 fewer kg than others of the same group (5).

6. Water Helps With Exercise

An important component of your weight loss plan is exercise, and water plays a major role to sustain you during your workout (5). According to Jampolis, water dissolves minerals called electrolytes – which include magnesium, sodium, and potassium – and disperses them equally throughout your body (2).

The electrical energy from electrolytes triggers muscle contractions that are necessary for movement. Thus, water helps your joints, connective tissues, and muscles to move correctly. It also helps your organs to work effectively as it increases activity during exercise (5).

Staying hydrated is important in exercise. Otherwise, you can have electrolyte imbalance, which eventually leads to cramping, fast protein breakdown, slow muscle build up, quick loss of body fluids through perspiration and evaporation (for temperature regulation), and fatigue (5)(2) – all of which can hamper the effectiveness of your workout (2).

On one hand, staying properly hydrated can improve your workout in a lot of ways, which include:

  • Maintaining blood volume to improve the expansion of blood vessels at the skin’s surface for heat release (2)
  • Decreasing fatigue to allow you to work out longer and shed more pounds (2)

That said, it’s important to keep water close and hydrate before, during, and after exercise, especially when working out in hot and humid conditions (5)(2).

7. Drinking Water Can Stimulate Metabolism

A registered dietitian nutritionist at Hilton Head Health, Elizabeth Huggins, explains the possibility for drinking water to aid with weight management by stimulating your body’s metabolism and calorie expenditure (2). A boost in metabolism has also been associated with a positive effect on energy level (6).

Drinking water can stimulate heat production (a.k.a. thermogenesis) in the body. The body expends energy to warm the fluid to body temperature. The more energy expended by the body, the faster your metabolism (or the process wherein your body transforms foods and beverages you consume into energy) will be (2).

In a study published in the Journal of Clinical Endocrinology & Metabolism in 2003, the metabolic rates of 14 healthy individuals had increased in an average of 30 percent after drinking around two cups of 71°F water (2).

8. Drinking Water Can Potentially Improve Motivation and Reduce Stress

Drinking water allows you to avoid experiencing dehydration symptoms like fatigue, dizziness, and confusion. A researcher from the 2016 mini-review found a link between dehydration and sleepiness as well as reduced alertness. Moreover, a study published in the International Journal of Sports Medicine discovered that dehydration increases the body’s production of the stress hormone, known as cortisol (2).

One of the consequences of dehydration is unclear thinking (7). According to Jampolis, these symptoms can affect your motivation to make healthy decisions for exercise and food choices.

Thus, by drinking water, you can keep yourself hydrated and keep your cognitive function in tip-top shape. Water helps to maintain oxygen in your brain, allowing you to function properly and maintain a healthy lifestyle and decision-making (2)(6).

What Happens When You Don’t Get Enough Water?

If you do not take in enough water every day, your body fluids become out of balance – leading to dehydration. In its more severe form, dehydration can be life-threatening (1).

Some symptoms of mild dehydration include: headaches, bad mood, constant hunger, and difficulty in concentrating. If you find yourself experiencing this, then you should drink more water (3).

Moreover, not enough water intake increases your risks for kidney stones and urinary tract infections (for women). Not drinking enough water can decrease your physical and mental performance, as well as your salivary gland functions – potentially leading to dehydration.

Tips to Improve Water Intake

Getting enough water daily is important for your health, especially when you are on a diet. To ensure that you get your fill throughout the day, here are some tips to get enough water on your everyday diet:

  1. Always choose water over sweetened beverages (7).
  2. Bring a water bottle with you and refill it throughout the day (7).
  3. Freeze some water-filled bottles and take one with you for some daily ice-cold water (7).
  4. Go for water when eating out. It can help you save some money and avoid unwanted calorie intake (7).
  5. Add a wedge of lime or lemon to your water to improve its taste and encourage yourself to drink more (7).
  6. Ensure that your kids are also getting enough water (7).
  7. Use a water tracker (available online) (4).
  8. Eat fluid-enriched foods like fruits and vegetables (4).
  9. Consider moderate caffeine consumption (up to 400mg daily) (4).
  10.  Choose water over sports drinks to rehydrate (4).
  11.  Take in some water with each meal and snack (8).
  12.  Add ice cubes that are made from fresh fruit to your glass of water (8).
  13.  Limit mineral water intake. They contain salt (8).
  14.  Fresh water works best in hydrating the body (8).
  15.  Milk – particularly full-fat milk for children below two years of age and low-fat for other age groups – is an important fluid (8).
  16.  Consider fresh fruit rather than fruit juices. You can have extra fibre and nutrients with less sugar (8).
  17.  Tea can also help meet daily fluid recommendations and be a source of antioxidants and polyphenols that can protect you from heart disease and cancer (8).

A Note on Fluid Retention and Water Intoxication

It’s a common myth that drinking water results in fluid retention. However, instead of keeping water, the body gets rid of excess sodium, leading to less fluid retention (8).

Nonetheless, the body will only retain fluid if there is very little water in the cells. Otherwise, if the body receives enough water regularly, there is no need to hold in water (8).

However, too much of anything can be dangerous, and the same goes with water. Although it rarely happens today, drinking too much water can cause hyponatraemia – which occurs when sodium in the blood drops to a dangerously low level (8).

Hyponatraemia also causes your kidneys to not filter enough fluid through urine and your blood to become diluted. It can lead to blurred vision, headaches, cramps, swelling of the brain, coma, and even death. However, it is more common in people with particular mental illnesses (like schizophrenia) or diseases, endurance athletes, and infants fed with over-diluted formula (8).

Take Home Message

Overall, water can be a great aid for weight loss and your overall health. Since it is calorie-free, it helps you expend more energy – which helps in movement during exercises for burning fat.

You can benefit greatly if you choose water over sugary beverages, as it is an easy way to cut back on calories and sugar. Although a great part of your diet and workout involves drinking plenty of water, it’s not the only thing that aids weight loss. Still, it’s a great first step.


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