How much water should man drink in a day

We all know staying hydrated is important. But how much water should you really be drinking each day?

You’ve likely heard sources claiming the “right” amount to be anything from four to 12 cups per day. However, the daily amount of water a person needs can be significantly individualized. For example, while four to six cups of water per day may be sufficient for the average healthy person when they are doing minimal physical activity, that number increases for people who exercise frequently.

Furthermore, certain health conditions may require reduced water consumption, while other conditions may necessitate increased water intake. Also, if you have a fever or an infection, or if you are losing fluids through vomiting or diarrhea, you may need to drink more water than usual to keep up or replace fluid losses. In addition, certain types of medications require that people decrease or increase their water intake. In all of these situations, it is best to follow a doctor’s guidance about the specific amount of water your body needs.

Other factors that affect how much water you need include:

• Where you live: People who live in hot, humid or dry areas need more water. In addition, you may need more water if you live at higher altitudes.
• Diet: People who drink a lot of coffee or other caffeinated beverages might lose more water through extra urination. They should consider drinking less caffeinated drinks and replacing them with water. Also, people who don’t eat many foods that are high in water (such as fresh or cooked fruits and vegetables) may need to drink more water.
• Environment and time of year: If you spend a lot of time outdoors in the sun, in hot temperatures or even in overly heated indoor areas, you may need more water due to increased perspiration. Similarly, people often need to drink more water during warmer months than cooler ones.
• Pregnant or breastfeeding: When you’re pregnant or nursing a baby, you need to drink extra water to stay hydrated, since your body is doing the work for two (or more).

Ways to Maintain Good Hydration

How do you know how much water your individual body needs? Rather than focusing on a specific daily amount, some experts recommend drinking water at a slow rate throughout the day. Hydration is easiest to achieve if constantly managed, so continually drinking water keeps your body in a consistent state of hydration.

“If your goal is to drink 64 ounces (8 cups) of water per day,” says UH registered dietitian Jennifer Kerner, “consider dividing the goal between three periods of the day, which would amount to about 2 to 3 cups in the morning, 2 to 3 cups during the afternoon, and 2 to 3 cups in the evening.”

You should also be aware of signs of dehydration, which include feeling weak, confused and dizzy; experiencing frequent headaches; and making urine that is dark in color.

Benefits of Drinking Water

In case you need further motivation to stay hydrated, here are just a few of the ways water can help your body function at a high level:

• Promotes less dry skin
• May help with weight maintenance and even weight loss when people replace drinking high-sugar drinks with drinking water
• Promotes healthy bladder and kidney function
• Improves digestion
• Promotes healthy joints

Lastly, here are some tips for staying hydrated:

• Carry a refillable water bottle with you wherever you go.
• Drink at least a cup or two of water with every meal.
• Drink a glass of water first thing when you wake up in the morning.
• Eat fruits and vegetables with high water content.
• Track your water with an app or in your day planner to make sure you’re getting enough.
• Try flavoring your water with lemon, lime or cucumber slices.

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Jennifer Kerner is a registered dietitian at University Hospitals Digestive Health Institute. Specializing in the provision of high-quality health care for patients with digestive and liver disorders and diseases, UH Digestive Health Institute is composed of gastroenterologists, hepatologists and surgeons working with nurses, dietitians and other providers – all committed to digestive health. For more information on UH Digestive Health Institute's services, call 866-844-2273.

Interested in trying our FREE 7-day healthy diet plan? Click here and choose between our meat eaters, vegetarian or vegan meal plans.

When it comes to the optimum amount of water to drink each day, everyone seems to have a different opinion. So should we be drinking 6-8 glasses, two litres, or even more? Do other liquids besides water count? And what are the warning signs that you're drinking too little water? We asked nutritionist (MBANT) Kerry Torrens for her expert opinion.

What are the benefits of drinking water?

When you stop to think that nearly two thirds of your body is water, it's obvious how important it is to stay well hydrated. Hydration is needed for digestion, for our heart and circulation, for temperature control and for our brain to work well. Water is, without doubt, the single most essential component of the human body.

Drinking water may boost mental performance

Research suggests that losing as little as 1% of your body weight in fluid may reduce mental performance, as well as potentially inducing fatigue and headache. This mild level of dehydration can easily occur over the course of a normal day’s activities, which highlights how important drinking little and often is for your health.

Drinking water may boost mood

Being dehydrated can also affect our mood and mental well-being, with studies suggesting that energy levels, cognition and emotions may all be affected.

Drinking water may boost physical performance

If you exercise, some studies suggest that as little as a 2% loss in your body’s water content may impact how well you perform physically. Dehydration may compromise your body’s ability to control its temperature, increase feelings of tiredness and, unsurprisingly, make exercise more difficult. However, research in this area is conflicting. One small study which kept athletes in the dark about their hydration status showed that dehydration made no difference to their performance. Clearly other factors besides temperature, climate and endurance also play an important role.

What are the symptoms of dehydration?

Thirst and passing dark-coloured urine are key signs that you may be dehydrated, as well as feeling lethargic, dizzy or having a dry mouth and lips. If you’ve been ill with diarrhoea and vomiting or fever, you can become dehydrated very quickly unless you replace the extra water lost from the body. In certain circumstances rehydration solutions can be useful because they help to replace the water, salts and minerals that your body has lost. If you are experiencing this, the NHS recommends that you consult a pharmacist who may recommend oral hydration sachets, and speak to your GP if your symptoms don't improve with treatment.

Checking the colour of your urine is widely considered to be the easiest and most practical way to assess your hydration needs – aim to pass urine which is light yellow to clear in colour.

Babies, children and the elderly are the most at risk of dehydration. Visit the NHS website to find out the signs of serious dehydration in adults and children under five years old.

Each individual's needs are unique to them and depend on their health, age, size and weight as well as activity levels, the type of job they do and the climate they live in. Drinking little and often is the best way to stay hydrated. In the UK, the Eatwell Guide suggests you should aim for 6-8 glasses of water and other liquids each day to replace normal water loss – around 1.2 to 1.5 litres. Water, lower fat milk and sugar-free drinks, including tea and coffee, all count.

In March 2010, the European Food Safety Authority (EFSA) issued a report suggesting an adequate total daily intake of 2 litres of fluids for women and 2.5 litres for men. This quantity includes drinking water, drinks of all kinds and the moisture available from the food we eat. On average our food is thought to contribute about 20% of our fluid intake which, therefore, suggests a woman should aim to drink about 1.6 litres and a man should aim for 2 litres.

However, there is controversy surrounding our hydration needs. Some argue that there’s a lack of scientific evidence to support the perceived health benefits of drinking the often-touted 2 litres a day, especially when it comes to those of us who live in temperate climates and who lead a largely sedentary lifestyle. However, the NHS still recommends that we consume around 6-8 glasses, with more required in hot weather or if exercising.

Do liquids other than water count?

Water, milk, sugar-free drinks and tea and coffee all count, but remember that caffeinated drinks like tea and coffee can make the body produce urine more quickly. Fruit juice and smoothies also count, but because they contain ‘free’ sugars (the type we are encouraged to cut back on), you should limit these to a combined total of 150ml per day.

Many of the foods we eat contribute to our fluid intake – for example, dishes like soup, ice cream and jelly, as well as fruit and veg with a high water content, such as melon, courgette or cucumber.

Can you drink too much water?

It is possible to go the other way and drink too much, although for most people with healthy kidneys this will be managed by urinating more frequently. Hyponatraemia is a condition caused by too much water which causes sodium levels to fall dangerously low. Athletes who participate in endurance events and take on too much fluid may be at risk of this condition.

Read more about how to stay hydrated while exercising.

When should I refer to my GP?

If you have not passed urine for more than 8 hours, you feel light headed or lethargic, are suffering confusion or have a rapid pulse rate, refer to your GP or healthcare practitioner. You may also wish to consult your GP if you have been experiencing consistent thirst, because this can be a symptom of a chronic health condition, such as diabetes.

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This article was last reviewed on 24 June 2020 by Tracey Raye.

Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food

All health content on bbcgoodfood.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.

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