We survive on food. The food we eat must first be digested to give us energy to survive. For this, all foods are first broken down after consumption.
The body can absorb various nutrients from the food that is broken down. Actually, digestive process starts in your mouth itself when you start chewing the food.
During the process of digestion, foods are transformed into energy or nutrients that the body needs for maintenance. Digestion involves both mechanical and chemical processes.
Studies say that it could take 24-72 hours to digest a meal completely. In fact, the overall duration of digestion could vary depending upon the food we eat and also from person to person.
When you first eat food, your teeth break the food into smaller fragments. Your saliva contains certain enzymes which further breakdown the food. Also, saliva lubricates the food pipe.
The chewed food mixed with saliva is then pushed inside by the tongue. Many muscles move in order to transfer the food from mouth to stomach.
When the food reaches stomach, the stomach secretes several enzymes and acids to break down the food chemically.
After food is broken down and reaches small intestine, some nutrients are already absorbed by the body. Both bacteria and certain enzymes break the food further.
Certain parts of food which are not absorbed till that point, reaches the large intestine. Also, all the waste material reaches the large intestine and spends more than a day there. The water content is removed from the wastes and is sent to the rectum to be excreted.
The waste is then sent to anus from where it gets excreted. This is the last stage of digestion.
Various other factors play a role in how foods get digested and how much time they take to get digested. Fatty foods may take longer time to digest. Some foods tend to digest faster. Also, it varies from person to person.