Our bodies are made up of a large proportion of water, in men that equates to an average of 60% of body weight and in women 50-55% body weight. Drinking the right amount of water is important for a number of functions in the body, including:

• regulating body temperature

• transporting nutrients and compounds in the blood

• acting as a lubricant and shock absorber in joints

• removing waste products from the body

• for our metabolism

We lose water through natural body functions throughout the day for example from breathing, sweating and through urine. It’s therefore important to keep our levels of water regularly topped up throughout the day to avoid dehydration.

How do you know if you’re dehydrated?

Common signs of mild dehydration include - dry mouth, headaches or dizziness, poor concentration, tiredness and needing to go to the toilet fewer than 4 times per day; urine will often be darker and have a stronger odor too.

Sweating through exercise can also cause dehydration so making sure you drink more during and around any exercise is very important. On the whole, for any moderate exercise water is fine for rehydrating and most people will not require a sports drink to stay hydrated. For anything over an hour of high intensity exercise, then drinks containing sugar and electrolytes may be better at replacing the extra fluid lost as sweat.

Very often we tend to eat when in fact we’re thirsty. Keeping yourself well hydrated ensures you can determine when you are actually hungry so you’re not eating unnecessarily.

How to include enough water each day

Current guidelines suggest drinking 6-8 glasses of fluids per day but you may need more depending on other factors such as the weather and how hot it is, your level of physical activity and your age.  

There are many sources of fluids that can count towards your 6-8 glasses per day. Here’s a run-down of different types and fluids and whether they can count towards your intake:

Water - the gold standard when it comes to fluid consumption! Water is low calorie and doesn’t contain any hidden sugars. Ideally the bulk of your daily fluids should be coming from pure, plain water.

Herbal Teas - if you’re not a fan of cold drinks with no flavor then herbal teas are the next best thing to water. Low calorie herbal infusions, some with added health benefits. Remember however that green tea still contains caffeine so it’s best to limit this to 2-3 cups per day as caffeine can act as a diuretic and therefore make you lose more water.

Tea & Coffee - although teas and coffees count towards your daily fluid intake, they also contain caffeine so too much can actually make you lose water. Therefore moderate amounts are key. In addition try to not sweeten teas and coffees with sugar as it increases their calorie content. Also be aware that many coffee shop coffee’s are made predominantly of milk (flat whites, cappuccino’s and lattes for example) so a few of these in a day will increase your calorie intake significantly.

Milk - although milk contains many essential nutrients (protein, some B vitamins, iodine and calcium), it’s also higher in calories than many other fluid options on offer and therefore should be had in moderation; either with your breakfast in the morning (cereal, granola, muesli, porridge for example) or in your tea/coffee. Some people like adding it into smoothies too. Ideally pick just one of these ways each day to have it in order to have it count towards your daily fluid intake.

Fruit Juices & Smoothies - Pure fruit juice, although seemingly healthy is very high in sugar. If you take one orange for example and squeeze it, how much juice do you get out of it? Not very much, or not a glassful at least. A whole glass of orange juice may require the juice from 6-8 oranges and therefore you’re consuming the sugar from that number of oranges! Similarly with smoothies, many are made up with lots of pieces of fruit, which once again increases the sugar content of that drink. According to the British Nutrition Foundation, just one 150ml glass of fruit juice or a smoothie counts towards your fruit and vegetable intake for the day.

Fizzy Drinks, Squashes, Juice Drinks - are all loaded with sugar, increasing your calorie intake with little nutritional value. It’s best to avoid these drinks as much as possible and try to swap them out slowly with some of the alternatives mentioned.

Alcohol - like caffeine, alcohol has a diuretic effect i.e. they actually make you lose more water through urine. Excessive consumption can therefore lead to dehydration. Not only does alcohol contain more calories (especially with mixers for spirits), it’s also important for our overall health to keep our consumption of alcohol to a minimum given it’s been linked to illnesses such as cancer, strokes, heart disease, liver disease, brain damage and damage to the nervous system.

Food - a diet that’s naturally higher in fruit and vegetables will help boost levels of hydration, particularly those which contain a high water content themselves like celery, lettuce and cucumber. Similarly, some preparation techniques when cooking also boost hydration e.g. soups and stews as you need to add water or stock to them anyway.

Practical Tips:

• Always take a refillable bottle of water round with you so you know you have water any time you need it.

• If you don’t like plain water then try flavoring it with fresh lemon, cucumber or mint which is not as calorific as fruit juices or squash. Herbal teas are also great and you can leave some at work in your desk to ensure you always have some of your favorites with you.

• Around exercise, aim to have an extra glass of water at least 30 minutes before you exercise and after you exercise too.

• Make sure the first thing you do in the morning is have a glass of water, so keep a glass next to your bed the night before when you go to bed.

• Ensure you’re meeting your 5 portions of fruit and vegetables per day given that fruit and vegetables naturally contain a high amount of water.

• Aim to have more water in the morning and during the afternoon rather than lots in the evening otherwise you may need to get up numerous times in the night, which will interrupt your sleep.

• Little and often. Preferably try to sip water rather than gulping down a glass in one go. This tends to keep you more hydrated; too much water in one go can also overload your kidneys.

Further Reading:

Healthy Hydration Guide for Adults and Teenagers - https://www.nutrition.org.uk/healthyliving/hydration/adults-teens.html  

Alcohol and Health Risks - https://www.nhs.uk/live-well/alcohol-support/the-risks-of-drinking-too-much/