How Long Does It Take To Digest A Meal?

Digestion is a process of breaking food down into nutrients the body can use. The entire digestive process may take several hours. 

How Long Does It Take To Digest A Meal?
By Pierre Mouchette | Bits-n-Pieces

What is digestion?
Digestion is a process of breaking food down into nutrients the body can use.  It begins in your mouth and ends at the terminal ileum (small intestine).  Seeing and smelling food is where the process starts.  In response, the salivary glands begin to make additional saliva-containing enzymes that initiate digestion.  Once the food is chewed and swallowed, the actual work begins in the stomach.  In the stomach, the food mixes with those digestive juices, creating a watery mixture that passes into the small bowel.  The walls of the small bowel absorb needed nutrients and water.  The colon (large bowel) then takes the unused material and prepares to eliminate it through a bowel movement.
 
How long does food take to digest?
The entire digestive process may take several hours.  A meal stays in the stomach for 40 to 120-plus minutes.  Then you add another 40 to 120 minutes for time in the small bowel.  However, the denser the food (more protein or fat it has), the longer it will take to digest.  Carbohydrates, such as plain rice, pasta, and simple sugars, average 30 to 60 minutes in the stomach.  
 
How long does it take water to digest?
Liquids leave the stomach quickly since there is less to break down:

• Plain water:  10 to 20 minutes.
• Simple liquids (clear juices, tea, sodas):  20 to 40 minutes.
• Complex liquids (smoothies, protein shakes, bone broths):  40 to 60 minutes.

 
What factors affect how long digestion takes
Factors that affect how long food digestion takes depend on the following:

• Body type
• Metabolism
• Medications taken
• Types of food eaten
• Level of physical activity and overall exercise fitness
• Living a sedentary versus physically active lifestyle
• Past surgeries you have had
• Stress level

Genetics and age matter, too.  Some people are born with faster metabolisms, and our metabolism and motility slow down as we age.  People also start developing medical conditions like high blood pressure, diabetes, and atherosclerosis.  Medications for these conditions can delay the digestion process.
Medicines and supplements that can affect how long digestion will take include:

• Arthritis medications.
• Anticholinergics.
• Antidepressants.
• Antispasmodic medications.
• Diabetes medications.
• Oral contraceptives.
• Parkinson’s disease medications.

 
Is it possible to know when your stomach is empty?
Just because you feel hungry does not mean your stomach is empty.  

• Hunger cues can be hormonally regulated.  So if you have high levels of hunger hormones floating around, you might feel hungry even if your stomach is full.
  
  
• Some medications, such as prednisone, increase your appetite by increasing appetite-stimulating hormones.  This means that you can feel hungrier more often when taking these medications, even though you have had enough to eat.