Does drinking while eating impair digestion?

Question

I have read many blogs and forums that either say eating and drinking at the same time is safe, good for you or bad for you. No sources are ever cited on any of the sites.

Does research exist to support either side?

Here are a couple of sites I have found:

• Alfred Chew's Blog

The explanation I got from most medical practitioners are that our digestive system works the best with less liquid in the stomach. Our 'stomach juice' (hydrochloric acid) reacts with the food we eat. It then passes through our small intestine and finally to the large intestine which we sometimes call it colon. The process is actually much more complex that what we discuss here.

In order for our digestion system to function well, we need to reduce the liquid content in our stomach. The food we eat will broken down easier and faster. We will have less problem with the digestion and the system digestive system will function perfectly. There will be less hydrochloric acid produced. Less work for your stomach which in turn your organ will last longer and healthier.

• Body Building Forum (Lots of competing answers)

• You should be drinking lots of water while eating. Part of the reason people say to drink water when dieting is that water is a very serious ingredient in the glycolitic cycle (i.e. ATP creation, transport, and destruction among a ridiculous amount of other things). In other words, water helps break down your food.

• Always drink 10-15 minutes before you eat. [...] Never drink while you eat [...] Don’t drink after your have eat for at least two hours (four hours if you had meat products like beef, pork, chicken, fish)

Answer 1

There is research that shows mice that don't drinking water while eating regulate their food intake better than those that drink. The title of this research is Gastrointestinal regulation of water and its effect on food intake and rate of digestion

This research shows a water-deprived animal is both thirsty and hungry, and eats less because dry food increases its thirst. The title is The interaction of hunger and thirst in the rat.

Both of these studies seem to indicate one will eat less if they do not drink water while eating, or don't drink water at all.

Another paper shows prandial drinking (drinking while eating) is learned in response to swallowing dry food with dry mouth. Which would point at cultures that have drier food would be more likely to drink while eating, and places that consume soups, and liquid food would drink less water.

Finally this paper shows different affects of water in combination with food intake and the affect on an animal.

My explanations are a simplification of complex research on the effects of water and food on digestion. There exists lots of research on studies with rats that go to understanding water and its affect with food. Search for citations of the papers I provided to learn more.