Why Coffee on an Empty Stomach Is a No-Go

Drinking coffee in the morning can irritate the gut as it increases acid production. This could trigger rather unpleasant acid reflux. According to WebMD, when acid reflux occurs, stomach acid flows into the esophagus and throat which causes heartburn.
“Normally, the LES (lower esophageal sphincter) closes as soon as food passes through it,” the site explains. “But if it doesn’t close all the way or opens too often, acid from your stomach can move up into your esophagus.” Explained Dr. Masarat Jilani.