Does eating standing up give you indigestion? Medical Myth

When you look at the causes of indigestion or functional dyspepsia, as it’s called in the medical literature, eating standing up doesn’t feature on the list. When likely causes such as stomach ulcers and gastritis have been ruled out, the management of dyspepsia can include changes to lifestyle, but this means eating a healthy diet, giving up smoking and reducing alcohol and coffee consumption. It doesn’t mean sitting down when you eat.
In fact doctors even recommend the opposite, if the pain is caused by acid reflux, when acid from the stomach comes back up into the oesophagus. This is where gravity can help; remaining upright during and after eating can keep the acid down in the stomach where it belongs. For the same reason, patients with reflux are advised to tip the head of their bed up, so that they sleep on a slant.
There are very few studies comparing fast and slow eaters, partly because it wouldn’t be easy to randomise people into eating at a particular speed and then to enforce that at every meal. A study from 1994 did include questions about eating speed in a survey of dietary habits. They found the speed at which you believed you ate had no relationship with the frequency of indigestion.  Research conducted in 2010 found the same, but these two studies rely on our ability both to judge our eating speed accurately, and to report it honestly.  
Professor Marc Levine, a radiologist at Hospital of the University of Pennsylvania x-rayed the stomach of a speed-eating champion after eating 36 hot dogs in ten minutes. The participant was happy to continue after eating 36, but the decision was made to terminate the study for his own safety. He didn’t have indigestion, while the unlucky man who’d volunteered to act as a control, felt sick after seven hot dogs and had to stop.  The x-ray showed that the speed-eater had trained his stomach to expand to such an extent that he no longer felt full when he’d eaten.
 This brings us to what could be the problem with eating fast – it’s not indigestion, butthe disruption of the usual mechanism that makes you feel full. But even here the evidence is inconsistent. Some studies foundthat eating fast leaves you feeling hungrier, causing you to eat more. Other studies have shown the opposite.
 Conclusion :Whether sitting or standing doesn't matters as long as it doesn’t make you feel ill at the time, there doesn’t seem to be any harm in it.