You Asked: Do I Really Need to Drink 8 Cups of Water Each Day for Health and Weight Loss?

By , SparkPeople Blogger
You've probably heard from lots of sources (including SparkPeople) that adults should drink eight (8-ounce) cups of water each day. But you might be surprised to know that there is no scientific evidence that supports this general advice. In fact, most experts aren't even sure exactly where that recommendation came from. One source of this myth might be a 1945 article from the National Research Council, part of the National Academy of Sciences, which noted that a "suitable allowance" of water for adults is 2.5 liters a day, although much of that already comes from water in the foods that you eat.
So why does SparkPeople emphasize water drinking? Here are a few reasons:
  • Most people today drink way too many of their calories from other beverages like soda, juice, flavored coffees and teas, sports drinks, fruit drinks, artificially sweetened drinks, etc. Drinking eight cups of plain water a day—in place of, not in addition to—these caloric beverages can help with weight management. Plus, most of these beverages don't offer any health benefits, while water does.
  • Starting a healthy lifestyle can be overwhelming. Even if you can't exercise five times a week, for example, you can probably still drink more water each day. By focusing on simpler goals like drinking water, you can begin to build momentum to reach other goals.
  • When it comes to weight loss, which is a goal for most members, water can also help you feel fuller. Thirst is often mistaken for hunger, so drinking a cup of water at the first sign of hunger is a good way to determine whether you really need to eat.
  • If you are following healthy, high-fiber diet, drinking additional water can help promote regularity and prevent the cramping and discomfort that often comes when you begin eating more fiber.
  • While you can get a lot of water from foods like water-rich fruits, vegetables, soups and more, following a reduced-calorie diet (for weight loss) means you're eating fewer foods in general. Eating less food means you're getting less water from food, so drinking plain water can help you meet your needs when food alone can't.
  • SparkPeople recommends at least three cardio sessions per week. If you are exercising, then you're losing water through increased sweating, which needs to be replaced. Learn more about drinking water during workouts.
  • SparkPeople recommends one to three strength-training sessions each week to build lean muscle. Muscle is made up of mostly water, so the more you train, the greater your body's water needs will be.
Some people worry that they could be drinking too much water. Water intoxication results when a dehydrated person drinks too much water without any accompanying electrolytes. You usually need to drink an excessively large volume of water in a very short period of time to be in danger of this, which is why it's not common. If you drink eight cups throughout the day, you should be fine.
So do you really need eight cups each day?
Like most recommendations, it varies. Everyone's needs are different and dependent on several factors, such as your weight, how much you exercise, how many water-rich foods you eat, the amount of muscle mass you have, the weather (such as heat and humidity) and more. But eight cups a day is still a good goal for the average person. The best way to find out how much water you need is to check the color of your urine. It should look like you squeezed a lemon in it. If it's much darker, try drinking a little more water.
If eight cups seems like a lot, consider how you could break it down throughout the day:  
Upon rising: 1-2 cups
After breakfast: 1 cup
Between breakfast and lunch: 1 cup
After lunch: 1 cup
Between lunch and dinner (when you start to feel hungry for a snack): 1 cup
After dinner: 1-2 cups

When you divide it throughout the day, those eight cups don't seem so daunting!

Learn more about how much water you need:
Water is a Secret Ingredient
12 Tips to Drink 8 Cups a Day
Healthy Beverage Guidelines