Do you remember how much water you consumed yesterday or so far today? You are not alone; many people struggle with drinking enough water during the day. Since water is the most essential of all nutrients, it is important to get an adequate amount every day. It is needed in amounts that exceed what your body can produce.
So how much fluid does the average, healthy adult need each day?
Though daily fluid intake recommendations vary by age, sex, pregnancy, and breastfeeding status, the U.S. National Academies of Sciences, Engineering, and Medicine determined that an adequate daily fluid intake is about:
- 15.5 cups (3.7 liters) of fluids a day for men
- 11.5 cups (2.7 liters) of fluids a day for women
What is often not understood, is that these recommendations include fluids from water, other beverages, and food. In fact, about 20% of daily fluid intake usually comes from food and the rest from beverages. You have heard the phrase, "Drink eight glasses of water a day?" This is a good place to start, and then adjust based on other factors.
- Exercise. If you do any activity that makes you sweat, you need to drink extra water to cover the fluid loss. It is important to drink water before, during, and after a workout.
- Environment. Hot or humid weather can make you sweat and requires additional fluid. Dehydration also can occur at high altitudes.
- Overall health. Your body loses fluids when you have a fever, diarrhea, or after vomiting. Drink more water or follow a doctor's recommendation to drink oral-rehydration solutions. Other conditions that might require increased fluid intake include bladder infections and urinary tract stones.
- Pregnancy and breast-feeding. If you are pregnant or breast-feeding, you may need additional fluids to stay hydrated.
Many articles are written about staying hydrated in the summer. Here are some reasons to stay hydrated in the winter.
Dehydration is accelerated in cold weather
Dehydration often begins as a minor headache and fatigue. As dehydration progresses, you might feel dizzy standing up too quickly; experience random muscle spasms and cramps, get a bad headache or migraine, and/or lose your ability to focus and concentrate.
Factors contributing to dehydration in cold environments include respiratory fluid losses and sweating that occurs when insulated clothing is worn during exercise. Dehydration can also occur because of low ingestion rates of fluid. Typically, individuals drink less fluids in the winter.
Another reason for potential dehydration in the winter, is that individuals working out in the cold may be reluctant to remove multiple layers of clothing to urinate (especially women), and they may purposely limit fluid intake.
Prevent Weight Gain by drinking water
Winter is a time we are inside more and might have access to higher calorie food choices. Instead of reaching for a high calorie snack, why not drink a glass of water? Drinking more water may also help with weight loss or weight maintenance. Drinking water before a meal reduces appetite. Drinking water instead of other beverages, which are often high in calories and sugar, can also help with weight maintenance.
Adults over age 60 may be consuming less fluids
Many older adults do not drink enough fluids to stay hydrated. Our sensation of thirst tends to decline with age. The average intake of beverages shows adults aged 60 and older, consume significantly fewer ounces of all beverage types compared to adults aged 59 and under—about 2 fewer cups per day, most of which is due to drinking less water. It is important that older adults drink plenty of water to prevent dehydration; this also aids in the digestion of food and absorption of nutrients.
Helpful Tips to Improve your Hydration
Choose healthy beverages by considering calories and nutrients.
- Best choices are calorie-free—especially water—or contribute beneficial nutrients and should be the primary beverages consumed, such as fat-free or low-fat milk and 100% juice. Coffee, tea, and flavored waters also are options, but limit sweeteners or cream.
- Avoid carbonated drinks that are high in sugar. Also, minimize beverages containing alcohol or caffeine, as these will cause your body to lose water.
Set a water-drinking goal. Establishing a daily water-drinking goal is one of the easiest ways to keep track of your water consumption. You can use an app to track progress or remind you to achieve these water goals. Also, make a habit of having a water bottle everywhere you go, including at your workstation; it acts as a physical reminder to stay hydrated.
Warm it up. Warm fluids may make it easier to reach your goal. Instead of forcing yourself to drink cold water, drink warm water (plain or infused), and healthy hot beverages like green tea, cinnamon tea, sugar-free hot chocolate, or hot soup. Green tea has about 30 - 50 milligrams of caffeine for an 8-ounce serving, black tea has 30 – 100 milligrams of caffeine and brewed coffee has 100 – 200 milligrams caffeine depending on the strength of the brew. For healthy adults, the FDA has cited 400 milligrams per day of caffeine as an amount not generally associated with dangerous, negative effects.
Try adding a flavoring. If you do not like to drink plain water, add a squeeze of fresh lemon or lime. Also, try calorie-free flavored seltzer or club soda.
References
1. "Report Sets Dietary Intake Levels for Water, Salt, and Potassium to Maintain Health and Reduce Chronic Disease Risk," U.S. National Academies of Sciences, Engineering, and Medicine. Last modified February 11, 2004. https://www.nationalacademies.org/news/2004/02/report-sets-dietary-intake-levels-for-water-salt-and-potassium-to-maintain-health-and-reduce-chronic-disease-risk. 
2. Thomas, et al. 2016. Nutrition and Athletic Performance, Med Sci in Sports Exerc. 48(3):543–568. https://pubmed.ncbi.nlm.nih.gov/26891166/.
3. Sarganas, et al. 2013. Association between water consumption and body weight outcomes: a systematic review. The American Journal of Clinical Nutrition, 98(2):282–299. https://doi.org/10.3945/ajcn.112.055061.
4. "Dietary Guidelines for Americans, 2020–2025," U.S. Department of Agriculture and U.S. Department of Health and Human Services. 9th Edition. Last modified December 2020.https://www.dietaryguidelines.gov/.
