Drinking Water While Eating: Good or Bad?

The topic of whether or not you should avoid drinking water while eating is a hot one.

People have come up with all sorts of reasons why you shouldn't drink while eating; it dilutes digestive juices, it increases your body's insulin response to the meal, it decreases stomach acid..... and so on.

But what does the actual science (not Dr Google) say?

First, I want to talk briefly about the process of digestion.

The digestion process starts in the mouth. When we chew food, we mix it with saliva that contains the necessary enzymes for digestion. Then, the softened food gets into our stomachs where it gets mixed with stomach acid.

Different foods, and different macros take different amounts of time to digest, but on average, the stomach needs about 4 hours to digest food before turning it into chyme (liquid). Chyme then goes into the intestine where it gives nutrients to the body.

Water, on the other hand, doesn’t stay in the stomach for a long time at all. It takes about 10 minutes to for the stomach to process 10oz of water.... LESS if your stomach is empty.

So does water decrease enzyme production? Not that science has shown. Water moves through you quickly. If you drink while eating, water doesn’t somehow form lakes in your stomach. It goes through the chewed food, moisturizes it and then leaves the stomach. All pretty rapidly. What DOES affect enzyme production is how thoroughly you chew your food. If you don't chew food enough it decreases enzyme production and can make digestion harder... but that's another topic.

Drinking water with a meal also doesn't decrease acidity. The stomach releases anywhere from 400 to 700 ml of stomach acid (hydrochloric acid or HCl for short) to help digest a meal. HCl creates a highly acidic environment in the stomach, with the average pH level of 2. Most drinking water has a pH level of ~7 (neutral). So this WOULD cause a subtle change in acidity, but water gets into the stomach with food, too. In fact most fresh fruits and vegetables are made up of >90% water! For example, on average, an orange consists of 86% water. Watermelon more. Cucumber contains a lot of water. So do grapefruits, strawberries and celery

So these foods can also impact the acidity level in the stomach.

But regardless , the change in the stomach’s pH with consuming “extra” water (for example sipping an 8oz glass) with a meal is pretty minimal, almost nonexistent. So while yes, water can mildly and temporarily increase the pH of the stomach, this response probably doesn’t really matter when it comes to heartburn. It only matters if the water prevents you from properly chewing your food.

Sometimes drinking fluid with a meal can cause you to not chew thoroughly. Chewing not only creates the mechanical breakdown of food, but also allows enough time for the mouth to mix food with saliva, release enzymes and start the digestion process. By allowing yourself to drink (lubricate) with a meal, you may not be chewing enough, and instead, just washing your food down with water. If you drink with meals just make sure you chew well and you'll be fine.

Does water slow or inhibit the digestive process? No. In fact, the opposite may be true. Water consumed before meals has been shown to stimulate the gastrointestinal tract and peristalsis, the involuntary contraction and relaxation of muscles that moves food through the GI tract. So it can aid in digestion. Water sipped during a meal (as long as it doesn't hinder chewing) can help soften and pass food as well.

Liquids also don’t influence the speed of digestion. There's a misconception that liquid pushes solid food into the intestine before it's fully digested and this can cause acid reflux and heartburn. There are no studies that prove this. Scientists have found that while liquid does leave the body faster than solid food, it doesn’t influence the speed of digestion.

So, is drinking while eating good or bad? If you drink while eating, it's fine. You're not going to hurt anything. Just be sure you sip, and don't allow your drinking to decrease the thoroughness with which you chew food.

There are even certain advantages to drinking while eating. Research shows that when a person takes short pauses to drink some water (sips not chugs) it slows down the eating process. As a result, people not only tend to eat less (which can be beneficial when it comes to weight management), but they also feel more satiated with their meal, because they eat at a rate of speed slow enough to allow the stomach to register "fullness" with the brain.