Hydrating Foods: Can You Eat Your Water?
Week one of our program is built on fruits and vegetables, and lots of them. One of the first questions people ask is, "Do I still need to drink all that water?"
Yes, keep drinking. But here's the part most people miss: you're also eating a lot of water that week, and it comes packed with the things that help your body hold onto it.
Which fruits and vegetables have the most water?
Most fruits and vegetables are 80 to 95 percent water. A few examples from the USDA food database:
About 95 percent: cucumber, lettuce, celery
About 91 percent: watermelon, strawberries
About 89 percent: broccoli
About 86 percent: apples, oranges
On a normal day, people get about 20 to 25 percent of their water from food. In a week built on produce, that share goes up.
Why food water works so well
Your body holds onto water best when it comes with a little sodium, potassium and natural sugar. That's exactly what fruits and vegetables carry, along with fiber.
A good example comes from a 2016 trial in the American Journal of Clinical Nutrition. Researchers had 72 men drink a liter of different drinks, then measured how much came back out over the next four hours. Milk and an oral rehydration drink were held onto best: about a fifth less urine than plain water. Coffee, tea, sparkling water, juice and sports drinks were about the same as water. The difference came from what was in the drink: minerals, some carbohydrate and protein.
A review by Rick Sharp at Iowa State found the same idea with food. After exercise in the heat, people who ate before drinking water recovered their fluid balance better than with water alone.
The way I put it to clients: water is water, but your body absorbs it best with nutrients. Plain water still counts. It just tends to pass through sooner when you drink a lot of it on an empty stomach.
What about "structured" or "crystalline" water?
You may have heard that the water inside plants is a special form your body absorbs better. There's no good human research behind that. Water is water. The real advantage of eating your water is everything that comes with it.
Does drinking water with meals hurt digestion?
You've probably heard you shouldn't drink with food because it "dilutes your stomach acid." We checked. In one study, a glass of water changed stomach acid levels for about three minutes. Then it was back to normal. Food itself tells your stomach to make acid.
What helps instead: a glass of water about 30 minutes before you eat. In two 12-week studies, people who did this lost a little more weight than people who didn't.
Sip with food if you're thirsty. If big glasses with meals leave you too full, or you deal with reflux, keep it to sips. That's about comfort, not harm.
How we use this in week one
Eat the produce. Six small meals, every two to three hours. Fruits and vegetables are light and leave your stomach sooner, so you'll be hungry again. That's the plan working.
Keep drinking water through the day. Our free Two-Hour Rehydration Method walks you through it: small sips, often, for two hours. Week one is also coffee-free, and here is why I take coffee out first.
Have a glass before meals.
Eat more, not less. The usual slip in week one is eating too little.
One safety note: week one is whole fruits and vegetables, not juice and not a liquid plan, and it's very high in fiber. If you have diverticulitis, trouble with fiber, or have had gut surgery, check with your doctor first.
Try this
For one day, count your servings of fruits and vegetables and notice how thirsty you feel compared with a normal day. Most people are surprised how much of their water came from the plate.
This post is for general information, not medical advice. If you have a health condition or take medication, check with your doctor before changing how you eat or drink.
Questions people ask
Which foods are the most hydrating?
Cucumber, lettuce and celery are about 95 percent water. Watermelon and strawberries are about 91 percent. Most fruits and vegetables land between 80 and 95 percent.
Do fruits and vegetables count toward your daily water?
Yes. On a normal day, food supplies about 20 to 25 percent of the water people take in, and the minerals and natural sugar in produce help your body hold onto it.
Is it bad to drink water while eating?
There is no good evidence that it harms digestion. In one study, a glass of water changed stomach acid levels for about three minutes. If big glasses with meals leave you too full, or you deal with reflux, just sip.
Sources
Maughan RJ, Watson P, Cordery PA, et al. A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index. American Journal of Clinical Nutrition, 2016;103(3):717-723.
Sharp RL. Role of whole foods in promoting hydration after exercise in humans. Journal of the American College of Nutrition, 2007;26(5 Suppl):592S-596S.
Popkin BM, D'Anci KE, Rosenberg IH. Water, hydration, and health. Nutrition Reviews, 2010;68(8):439-458.
Karamanolis G, et al. A glass of water immediately increases gastric pH in healthy subjects. Digestive Diseases and Sciences, 2008;53:3128-3132.
Dennis EA, et al. Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity, 2010;18(2):300-307.
Parretti HM, et al. Efficacy of water preloading before main meals as a strategy for weight loss in primary care patients with obesity: RCT. Obesity, 2015;23(9):1785-1791.
U.S. Department of Agriculture, FoodData Central.
