When it's hot, hot, hot, we often find ourselves reaching for more to drink. Makes sense, right. You're thirsty, so drink up? But the advice on the specific amounts can be a bit confusing.
There are some really GREAT reasons why drinking more water is a good idea for health in general but also for weight loss. Ready? Here we go:
Water can help you burn more calories
In adults, studies show being well hydrated increased calorie burn by 24–30% within 10 minutes of drinking water and the effect lasts at least 60 minutes. Another study of overweight women looked at what happened when they upped their water intake to over 1 litre per day. Here's what: over the course of the year, this lead to an extra 2 kg (4.4 lbs) of weight loss. The effects were more marked when they drank cold water, given your body uses extra energy (or calories) warming the water to body temperature. And these women did nothing else to their diet and lifestyle but drink more water. Yay! (Note, in this hot weather, you'll definitely want to be drinking way more than the women in the studies).
Drinking water before a meal helps reduce your appetite
You might have heard this before and the science really does back it up - especially when you hit middle age. The science tells us that 'older adults' lost more weight (2kg or 4.4lbs) in the research group than those who no water before a meal.
There's a caveat I'd like to add... As you age, you produce less stomach acid, which is needed to break down the protein in your food. So if you know you already have digestive issues, this might not be the best approach unless you take a digestive enzyme to ensure you break down your food properly. Digestive enzymes also reduce as you get older, so this isn't a bad thing from your 40s onwards. You'll find these at any health food shop.
Drinking more water lowers your calorie intake
It makes logical sense that, if you're drinking water to hydrate rather than other drinks like juice and fizzy drinks, which may be laden with calories and/ or sugar, your body isn't getting that extra energy - and your blood sugar isn't going to spike which, in itself, can promote weight gain.
So you're probably now wondering this...
How much water should I drink?
Do you drink too much or not enough? here are two common myths about hydration you can now stop believing now!
You could ask anyone in the street, and most people would know that the recommended fluid intake is 1.5 to 2 litres or 6-8 glasses. Indeed, that is what the Eatwell Guide recommends. The NHS, although quoting the Eatwell Guide as well, suggests that we drink “plenty of water”. But how much is ‘plenty’? Is there, perhaps, an upper limit?
In 2007 seven, a 59-year-old woman nearly died after drinking too much water.
Admittedly, very few people manage to drink that much, even if they try. Incidents like this are sporadic, but it happens occasionally and shows that even water can be detrimental if overconsumed. In this particular case, the woman reported having drunk more than half a pint of water every 30 minutes in an attempt to relieve a urinary tract infection.
In reality, many people struggle to drink the recommended 6-8 glasses per day. But who says you have to? In 2002, researcher Heinz Valtin went in search of the source of this often-quoted recommendation. He was unable to find it. There is no scientific evidence for the advice to drink 6-8 glasses per day as far as he could see.
The absence of evidence is not surprising, considering that the water requirement changes from person to person and from day to day. How much you need to drink depends on your gender, age, weight, activity level, climate, altitude and medication … to name but a few.
Some people need just S glasses of fluids a day; others need considerably more. Despite the difficulty of working out how much every one of us needs to drink, we seem to manage quite well. One paper on the subject concludes that healthy people regulate their daily water balance “with precision”.
No mean feat. After all, the parameters for hydration change all the time. Our location, the weather or our activity levels – or all three - may be different today than yesterday, and so is our water need.
It appears, therefore, that there is no need to lose sleep over adequate fluid intake. Apply common sense.
If you are thirsty, drink. If you sweat a lot, drink more than you normally would.
That said, thirst can be deceptive, especially in older people. Several parameters, such as blood pressure, blood volume, electrolyte levels and certain hormones, signal the brain and the kidneys when water levels are low. The kidneys will then hold back and excrete less water, while the brain triggers the thirst sensation. This works quite well until later in life. Older adults do not sense thirst as easily as younger people do.
Another indicator for dehydration is the colour of your urine. If it is dark like apple juice, it is time to drink. In my house, we call this 'old man wee'. If your urine is straw-coloured, your hydration level is about right. If your urine runs clear like water, there is no need to drink more right now. In my house, this is know as doing a 'see-through wee'.
The advice to drink 6-8 glasses a day is usually closely followed by the reminder that you must not try and hydrate by drinking alcohol or caffeinated drinks. These beverages are said to be diuretic and make you pee more, thus accelerating dehydration. However, a study looking into this found no difference in hydration levels of young men, regardless of whether they consumed caffeinated or non-caffeinated drinks.
A 2015 study comparing the effects of water, cola, and juice, again, found no difference.
There are, of course, many reasons to skip on soft drinks - sugar, artificial sweeteners and phosphates come to mind – but dehydration isn’t one of them.
Alcohol is a different matter. In small doses, such as half a pint, even beer can be hydrating, provided that the person drinking it is dehydrated to begin with, but more alcohol in slightly better hydrated people does lead to greater urine output, which is code for seeing more!
In summary, no one can tell you how much you need to drink in a day. Perhaps your doctor could, if they took blood and urine samples, but since that is not practical on a daily basis, you’re on your own. Go by how thirsty you are and the colour of your urine.
Of course, you can drink beverages other than water to hydrate: herbal teas, fruit infusions, vegetable juices, kombucha, and tea and coffee all count. Even fruit juices and soft drinks are hydrating but are best avoided for other reasons, just like tea and coffee should be sugar-free. Don't forget that food can be hydrating, too. Fresh fruit and vegetables, such as watermelon and cucumber, contain water, and sometimes quite a lot of it. Soups are another excellent source of fluids.
For healthy people it isn’t too difficult to stay hydrated. In this hot weather, it does make sense to drink more - let your body tell you how much!