On Nutrition

When I ask people how much water they drink daily, the answers I get are all over the map, from almost none to more than 100 ounces. That’s quite a range, but how much is optimal? You’ve probably heard the recommendation to drink eight 8-ounce glasses of water, or 64 ounces, per day. While that’s an easy-to-remember place to start, that recommendation itself isn’t based on … anything.

Official recommendations are that women get about 11.5 cups (92 ounces) of fluids from foods and beverages per day, and men get 15.5 cups (124 ounces). We typically get 20% of that from food — think fruits, vegetables and high-liquid dishes such as soups — leaving a balance of nine cups for women and 12.5 cups for men. However, many factors other than gender affect how much water you need, including age, life stage, activity level and overall health.

  • Women need more water during pregnancy and while they are breastfeeding, because their bodies are doing the work for two (or more).
  • If you get a lot of general activity during the day — maybe you walk or stand a lot — you’ll need more water than someone who spends their day sitting.
  • If you exercise or do any intense activity, you will need to drink more to compensate for water lost through sweating.
  • If you have an infection or a fever, especially if you’re losing fluids through vomiting or diarrhea, you’ll need to drink more water. Individuals with certain chronic health conditions may need to either limit or increase water intake.

Get too little fluids, and you can tip toward dehydration, which could result in more frequent headaches, dizziness or constipation. Get too much fluid — maybe you already eat a lot of fruits and vegetables and you’re chugging water all day on top of it — and you can become overhydrated, which is what happens when you ingest too much water in comparison to your intake of electrolytes and calories. Electrolytes are minerals — sodium, calcium, potassium, magnesium, chloride and phosphate — that keep your body’s pH level balanced and keep your nerves, muscles heart and brain working as they should. Your body will first respond by flushing water out to restore balance — you’ll find yourself peeing frequently — but in extreme cases, overhydration can be dangerous. For example, when endurance athletes drink too much water and consume too few electrolytes during exercise.

As we head toward summer, here are some tips for staying appropriately hydrated:

  • Honor your thirst. If you are thirsty, drink some water. This is especially important if you are active or living or traveling in a hot or dry climate.
  • Enjoy summer produce. Juicy fruits and leafy green salads are water- and nutrient-rich.
  • Sip early and often. Start your day with a glass of water (keep a glass by your bathroom sink or your coffee maker), then drink some water with meals and sip more between meals. This also makes it possible to taper off water intake as you get closer to bedtime.
  • Keep water handy. Carry a refillable water bottle in your car and keep a glass at your desk or table so it’s there when you want to reach for a drink.
  • Jazz it up. If you get bored with plain water, add a squeeze of fresh lemon or lime juice, toss in a few cucumber or ginger slices or add some fresh basil or mint leaves.