“You are what you eat”, a statement emphasizing healthy eating was derived from a phrase in 1826 “Tell me what you eat and I will tell you what you are”. Research on the digestion and absorption of food has clarified the relationship between content, volume and timing of meals vis a vis our sense of well being.

Certain foods have a direct effect on the GI tract. Mints, chocolate and alcohol relax the lower esophageal sphincter (LES, a sphincter which separates the esophagus from the stomach); relaxation of this sphincter promotes reflux of stomach contents into the esophagus. It has been the custom in Middle Eastern culture to burp following a meal as an expression of enjoyment of a meal – mint provided at the conclusion of meal relaxes the LES and promotes reflux of swallowed air into the esophagus allowing a polite burp. Fat in a meal (animal or vegetable in origin) slows the emptying of the stomach and is the basis for prolonged abdominal fullness following a meal with large amount of fat (think of your last Thanksgiving Day meal). The slower emptying of the stomach allows the small intestine to maximally absorb this high fat meal. Light exercise such as walking after a large meal facilitates gastric emptying and reduces abdominal fullness more rapidly than being sedentary. It should be noted that the small intestine is very efficient in extracting nutrition from the contents of a meal so there is no reduction in absorption of calories from a high fat meal with such exertion.

The volume of a meal effects the emptying of the stomach – a larger meal requires more time to empty from the stomach. Of these two factors – fat vs. volume – fat has the greater influence on gastric emptying. This is the reason why following certain large ethnic meals (e.g. Chinese) one feels hungry a short while after completing a meal.

The timing of a meal also influences one’s sense of well being. The process of digestion of a meal (stomach grinds food into small particles) and the absorption of meal by small intestine requires 2-3 hours. Sleeping shortly after eating or exercising can interfere with this process. Sleeping typically requires a horizontal position which promotes gastroesophageal reflux. Exercising intensely following a meal diverts large portion of blood flow away from the GI tract to muscles which delays digestion and absorption which causes nausea, abdominal pain, and diarrhea.

With this understanding of GI tract physiology we will turn in our next discussion to:

“An evening in Naples, Florida – a recipe for reflux!”