Study: Drink 2/3 of Your Weight in Water a Day to Lose Weight

We all know we should be drinking more water, but it's harder than it sounds. You wake up, drink coffee, get busy at the computer, and before you know it, it's nearly noon and you're hungry and you haven't had a single glass of water.

Now, nutritionists believe that drinking more water can help you have a healthier digestive system, increase energy, stay alert while working at your desk, quell hunger cues, and even lose unwanted pounds. The problem is that while we all prioritize the foods we are eating, we don't recognize that we are dehydrated most of the time, especially during summer.

The right amount of water to drink a day is astounding. Here is a formula that involves simple math: Multiply your weight in pounds by 2/3 and that is the number of ounces of water to drink in a day. That means if you weigh 150 pounds you need to strive for 100 ounces of water a day. If you want to punch this into your calculator take your weight (for example, 130 pounds) times .67 (2/3) equals 87 ounces. For a 180-pound person, you should drink 120 ounces a day. That's ten full tall glasses of water. Start now, as you're reading this.

The best way to achieve this: Start by drinking a full tall glass of water in the morning, when you wake up, then another before lunch, and two more in the afternoon. If you measure your glass (a tall glass holds about 12 ounces) and find that it holds 10 to 12 ounces, you need to drink 8 to 10 of those, depending on your weight, every day. Sorry, but coffee and tea don't count since those are diuretics, meaning they act to dehydrate you by causing you to pee.

Water is water; you can add lemon to it for added taste and the health benefits of vitamin C, since adding lemon can get you to 1/3 of your overall vitamin C for the day. If you prefer, add cucumbers or strawberries or other taste to give it an infused taste that helps you drink more,  if you prefer the sweeter taste. And no, spirits, wine, and beer don't count, since they are full of calories and alcohol. What does count: Fruit that's full of water like watermelon, and even some vegetables can help get you there. This chart shows which fruits and vegetables contain the most water from most to least.

The health benefits of water are many, according to this study, including cellular function. Your body regulates itself depending on whether you have adequate hydration and when you don't drink enough, your cells shrink, actively age and the body makes compensations that are not optimal for the long-term health. When you have enough water your cells function better, your mood and cognitive function improve and your body works like a well-oiled machine. Ironically children need to replace fluids more often than older people but are worse at recognizing when they're thirsty.

Hydration is signaled visually and by taste. You'll see water and realize you're thirsty, but often you have no idea that you're dehydrated until symptoms like headache and lack of focus occur: If you have a headache, feel spacy or tired, chances are you need to drink more water. Hydrating immediately may help get rid of a headache or give you a needed boost of energy, but the recommended daily amount is rarely met. If you weigh 150 pounds or more, and you aren't drinking 8 to 9 glasses of water a day you are falling short.

Drinking enough water helps your body feel nourished and refreshed, energized, and clean. You will notice increased energy, better athletic performance, clearer, more glowing skin, and you can even lose more weight by flushing out waste your body and feeling fuller longer.

The Beet wants to help you reach that goal: Take the Hydration Challenge for a week to get you in the healthy habit of drinking more water and maintaining your weight-loss goals. The VegStart Diet, created by Registered Dietician Nicole Osinga, recommends the higher threshold of getting 2/3 of your weight in ounces as the amount of water a day you need to help you lose weight. Other sources recommend a minimum of half your weight in ounces of water a day. The extra water Osinga recommends is to aid in feeling fuller longer, and aiding weight loss.

From the hydration study: Cognitive performance is affected by hydration: "Water, or its lack (dehydration), can influence cognition. Mild levels of dehydration can produce disruptions in mood and cognitive functioning.  In a series of studies using exercise in conjunction with water restriction as a means of producing dehydration," the authors found "cognitive performance in healthy young men and women athletes... the only consistent effect of mild dehydration was significant elevations of subjective mood score, including fatigue, confusion, anger, and vigor."

Yes. By drinking enough water you can suppress your appetite and eat less throughout the day, increase your body's metabolic rate, and increase your energy levels which will allow you to be more active. In addition, drinking more water helps the body stop retaining water and flushes everything out of your system, helping you to drop a few pounds.

What happens in the bathroom stays in the bathroom, but it's also one of the best places to make sure you are hydrated. Urine color is the best indicator of your hydration level. "Pale yellow urine that looks like lemonade" is the goal, according to Healthline. "Darker urine means you need more water. Colorless urine means you are overhydrated."

Yes, overhydration is possible, especially during an athletic event when you're sweating out important electrolytes and replacing fluids with water that does not have salt and potassium, essential for healthy cell function. "Overhydration can lead to water intoxication. This occurs when the amount of salt and other electrolytes in your body becomes too diluted," according to Healthline. "Hyponatremia is a condition in which sodium (salt) levels become dangerously low. This is the main concern of overhydration. If your electrolytes drop too low too quickly, it can be fatal. Death by overhydration is rare, but it can happen." Just make sure if you're training for a long-distance event in hot weather to put electrolyte fluids in your water bottle.

Endurance athletes, triathletes and marathon runners have a higher risk of overhydrating because they drink more water than electrolyte fluids, and deplete their vital salts. If you're not in that category, chances are you need to drink more water not less.

1. Drinking water can improve focus and cognitive performance. 

Dehydration can produce negatively affected your mood and cognitive function. This may be of special concern in the older people, young children, hot weather, or during an athletic performance such as running a race, playing tennis, and other sports that rely on focus and a strong mindset.

In a study by a group of nutritionists who compared age and cognitive function against mild dehydration, the results found: "Mild dehydration produces alterations in a number of important aspects of cognitive function such as concentration, alertness, and short-term memory in children (10–12 y), young adults (18–25y) and in the oldest adults, 50–82y. As with physical functioning, mild to moderate levels of dehydration can impair performance on tasks such as short-term memory, perceptual discrimination, arithmetic ability, visuomotor tracking, and psychomotor skills."

When you're taking a test or studying for an exam, make sure to have water at reach so you can stay focused and accomplish your goals.

2. Drinking water can help you lose weight by lowering total energy intake or altering metabolism. 

Drinking water may promote weight loss. In a study conducted by researchers at the Obesity Society, they tested for "associations between absolute and relative increases in drinking water and weight loss over 12 months." Data was collected from "173 premenopausal overweight women (aged 25–50 years) who reported l/day drinking water at baseline."

The study explains: At each time point, mean daily intake of drinking water, noncaloric, unsweetened caloric (e.g., 100% fruit juice, milk) and sweetened caloric beverages, and food energy and nutrients were estimated using three unannounced 24‐h diet recalls. Beverage intake was expressed in absolute (g) and relative terms (% of beverages). Mixed models were used to test for effects of absolute and relative increases in drinking water on changes in weight and body composition, controlling for baseline status, diet group, and changes in other beverage intakes, the amount and composition of foods consumed and physical activity." After the twelve months, the study found that "absolute and relative increases in drinking water were associated with significant loss of body weight and fat over time," concluding that drinking water may promote weight loss in overweight women who are dieting.

As a result, weight loss is made up of many factors such as physical health such as exercise, mental health such as lowering your stress levels and getting a good night's sleep and eating a clean diet full of natural plant-based foods. Increasing your water intake can help you stay on track and add to the weight loss effect at a very small rate. However, you should try to accomplish all three states and hydrate your body for fuel and boosting your metabolism.

3. Drinking enough water can help your kidney function.

Drinking enough water protects your kidneys. "The kidney is crucial in regulating water balance and blood pressure as well as removing waste from the body," according to a study by The National Institutes of Health. "If the kidneys economize on water, producing more concentrated urine, there is a greater cost in energy and more wear on their tissues. This is especially likely to occur when the kidneys are under stress, for example when the diet contains excessive amounts of salt or toxic substances that need to be eliminated. Consequently, drinking enough water helps protect this vital organ," the NIH concludes.

4. Drinking enough water can help your athletic performance.

When a person becomes dehydrated they experience fatigue and reduced endurance. Just like when you go out for a long run and notice the difference in your energy when you're dehydrated. You start to slow down, think of excuses, and feel like you need to stop. Make sure you drink water before any physical activity, even if you go for a  walk or practice yoga.

"Dehydration alters cardiovascular, thermoregulatory, central nervous system, and metabolic functions. One or more of these alterations will degrade endurance exercise performance when dehydration exceeds 2% of body weight. These performance decrements are accentuated by heat stress. To minimize the adverse consequences of body water deficits on endurance exercise performance, it is recommended that fluid intake be sufficient to minimize dehydration to less than 2% of body weight loss, according to researchers at the US Army Research Institute of Environmental Medicine. 

Drinking water can reverse dehydration and reduce oxidative stress from exercise and physical activity. Before you perform any physical activity, make sure you hydrate beforehand and after. Sometimes if a person hydrates during the workout, the stomach can cramp so it's best to be hydrated prior to your sport.

5. Drinking enough water can improve your skin.

In magazines, on TV, and written in beauty blogs, most people believe that drinking more water will clear your skin and give off a glowing effect. Although there are many factors involved such as genetics, exposure to the sun, and the overall way you treat your skin, water has a simple effect that can help improve your skin.

Even though dry skin is usually caused by exposure to dry air, the water that passes through the inside of your body to your epidermis, or the skin layer can improve skin hydration. "Water intake, particularly in individuals with low initial water intake, can improve skin thickness and density as measured by sonogram, and offsets transepidermal water loss, and can improve skin hydration," according to a study by the International Journal of Cosmetic Science.

Drink more water as a natural way to cleanse your skin. Infuse your water with fruits and veggies like lemon, lime, strawberries, cucumbers, and more for taste and immune-boosting properties.

6. Drinking enough water can prevent you from getting headaches. 

People who experience frequent headaches should see a doctor but first, make sure you are hydrated. Dehydration can lead to headaches just like an empty stomach can lead you to hunger.

In a study, researches examined increased water intake and headache symptoms in headache patients. "In this randomized trial, patients with a history of different types of headache, including migraine and tension headache, were either assigned to a placebo condition (a non-drug tablet) or the increased water condition. In the water condition, participants were instructed to consume an additional volume of 1.5 L water/day on top of what they already consumed in foods and fluids. Water intake did not affect the number of headache episodes, but was modestly associated with a reduction in headache intensity and reduced duration of the headache." Results explain that water intake can help relieve head pains but the ability to prevent headaches is still unknown.

If you already have a headache, try drinking water to alleviate the pain. However just because you're staying hydrated throughout the day doesn't mean you won't get a headache. The ability to prevent the headache is uncertain and caused by many internal and external factors such as stress and staring at a computer screen.

The Hydration Challenge is on. Follow along on The Beet's IG and FB and post how you're doing today.