If you dislike drinking copious quantities of plain water, this story is for you. A recent press release from the National Academy of Sciences poked holes in the 8 glasses of water a day recommendation. Despite the wide spread acknowledgement of the “8 a day” rule, there appears to be very little evidence to support the need for this quantity of “water”. The key word here is water. According to the National Academy report the average sedentary woman takes in about 2.7 litres of fluid from both food and water. The average man consumes about 3.7 litres. Those amounts appear to be adequate. Approximately eighty percent of our fluid comes from beverages and 20 percent comes from foods such as fruits and vegetables. So when you do the math the average woman is drinking about 2 litres of beverages ( 8 cups!) and the average man drinks about 3 litres (12 cups). The eight a day rule DOES still apply as a minimum level to achieve. The difference may be how you apply the rule. Instead of 8 cups of water, you can count any non-alcoholic beverage toward your fluid intake. Juice, milk, fruit drinks, sports drinks, pop and yes, even coffee and tea can count toward your 8 cups of fluid per day. Coffee lovers around the world rejoice. Studies have shown that the amount of caffeine in coffee is not enough to cause an appreciable loss in body water. You may find this hard to believe when you add up the number of times you hit the bathroom after your extra large morning java. The bathroom breaks appear to be more dependant on the volume of fluid you drink than the type of drink. In other words if you drank that same quantity of water in the morning, you would have roughly the same number of trips to the bathroom. Before you trade in your Aberfoyle Springs for a Timmy's, there are a few other things to keep in mind. Caffeine is still a stimulant, it interferes with the absorption of several important nutrients and it is addictive. That would explain the pounding headache for the first few days of Lent, if you gave up coffee. That said, there is nothing wrong with 1-2 cups of coffee a day as part of your eight to twelve required cups of fluid. If weight loss is your goal, then water should certainly make up the majority of your daily fluids. Even coffee can add unwanted calories if you fall into the “double-double” habit. Juice, milk, pop and fruit drinks all contribute roughly the same amount of calories per cup. If you enjoy fresh fruit regularly there is no need to consume fruit juice. Milk on the other hand is an excellent source of calcium, protein and vitamin D. Skim milk should be on the list of anyone trying to maintain or lose weight. Recent research suggests that the calcium found specifically in low fat dairy products helps our body to burn body fat more efficiently. Therefore for weight loss, a woman's fluid intake might look something like 5 cups of water, 2 cups of skim milk and an optional 1 cup of coffee in addition to lots of fruit and vegetables. A man seeking weight loss would have a similar pattern however adding up to 12 cups or 3 litres of fluids from beverages. If you are not seeking weight loss, your 8 to12 cups can come from any combination of non-alcoholic beverages. It's still worth seeking out nutrient dense beverages such as milk or 100% fruit juice. Keep those empty calories in pop, sport drinks and fruit drinks under check. One last point to note is that the current review of fluid intake was only done on “sedentary” individuals. If you are active or exercise regularly you may need more than 8-12 cups of fluid per day. I'll cover the important topic of exercise hydration next Thursday. Until then, keep those fluids coming.
Heidi Smith is a Registered Dietitian from the Health and Performance Centre. She is the author of the book “Nutrition for the Long Run - A nutrition handbook for runners, walkers and active individuals”. Her column runs every Thursday