Fiber isn't usually considered a nutrient, since it can't be digested by humans. We can actually live without fiber, but as you will see we are much more healthy and comfortable if we do get some fiber in our diets. Water isn't commonly thought of as a nutrient either, but it is necessary for us to live. All the ecosystems on the planet depend on water. Without it we wouldn't be able to grow our food supply, and all the carbon-based life forms here on earth would die, many within a few days, if they didn't have access to water.
Fiber is not an essential nutrient, but it can make your life a lot more pleasant. Here are some of the things that fiber can do for you.
There are two types of dietary fiber
Dietary fiber is measured in grams (g). No distinction is made between how much soluble and insoluble fiber you need each day. As a rule of thumb you should try to get fiber from a wide range of fruits, vegetables and whole grains. See your daily requirement for fiber.
About two thirds of our bodies are water, and all of our cells require water to work properly. We can go for weeks without food, but will only last a few days without water.
Water is used to cool the body through perspiration, to move food through the digestive tract, to make up most of the volume of our blood and other body fluids, including the fluid surrounding the joints, brain, eyes and spinal cord, mucous and saliva. Digestion of proteins and carbohydrates depends on water.
Our bodies are very good at regulating water balance. If the balance is low, the kidneys will conserve water by concentrating the urine, and we become thirsty, which reminds us to take in more water. About three fourths of the water we lose each day is through the kidneys. We also lose water through perspiration, water exhaled in the breath, and water in the feces. The amount of water depends on many factors, such as our size, the temperature or climate where we live, activity level, age and state of health. For this reason there is no daily requirement set for water, however an Adequate Intake has been calculated for different age groups. You would need to adjust this if you are extremely active, if you live in a very dry climate, etc. See the Adequate Intake level and find out more about the AI.
On the average, a person needs 8-12 cups of water per day. This may sound like a lot, but you get a lot of water without even realizing it. Crisp vegetables such as lettuce and celery can be 90% water. Even meats and grains contain some water. All beverages, including milk, are a source of water. You get water through food preparation of things such as soups and hot cereals, rice and other grains cooked in water. You should also try to drink 6-8 cups of water during the day to make up the difference.
Bottled water has become a huge industry, at least in the United States. According to the International Bottled Water Association (IBWA), Americans bought 5 billion gallons of bottled water in 2001. Is it worth it to buy bottles of water when you can get it from the tap for the cost of your city water bill? Many people believe bottled water is more pure, but this isn't necessarily true. In the US the Food and Drug Administration regulates both bottled water and tap water, and in most instances the standards for the two are the same. A company that bottles water may go above and beyond the standards to filter and purify their product, but they are not required to do this. You would need to check out each individual company to find out the standards of their water.
There are times when it makes sense to use bottled water. If you are on the road and want to have a ready water supply, if your tap water tastes really awful because of metals or chlorine, if you happen to know there is a contaminant in your city water or your well, bottled water makes sense. If you drink mostly bottled water you may not be getting any fluoride, which is often added to a public water supply. If this is an issue you should choose a brand of bottled water with fluoride added.
Here in the United States we have the luxury to choose bottled water or tap water, and worry about little things like a metallic taste or whether fluoride is added. In many other parts of the world water is a precious commodity, and people feel lucky to have any at all. Many countries are just plain short of water because of a desert climate, especially developing countries where they don't have the infrastructure to bring water in. For many other people its a question of clean water. Because of poverty, natural disasters or war, they don't have access to a clean water supply, and are at a risk for all sorts of diseases such as cholera, hepatitis or schistosomiasis. Some areas have high levels of natural fluoride, arsenic or other toxic metals in the water and don't have the means to remove it.