Digestion Process: Timeline and How it Works (2024)

Generally, food takes 14 to 58 hours to move through your digestive tract. However, the exact time depends on several factors, such as the types of foods you’ve eaten, genetics, and health conditions.

Digestion is how your body breaks down food and extracts the nutrients it needs. Anything left is a waste product, which your body removes.

This process is sometimes known as whole gut transit time (WGTT), which refers to the time it takes for food to move through your gastrointestinal (GI) tract from the mouth to your anus.

Food generally takes 14 to 58 hours to move through the digestive tract, with the average time being 28 hours.

However, some research suggests it may take up to 5.5 days for food to fully digest.

How long it takes for food to digest will vary widely from person to person and depends on several factors, such as:

• dietary and lifestyle habits
• gut microbiome
• genetics
• sex assigned at birth
• stress
• underlying health conditions
• taking certain medications

Keep reading to learn more about how long it takes to digest food, how digestion works, and how to improve digestive health.

On average, WGTT takes 28 hours.

However, the range for digestive transit time is also broken down into smaller segments:

• Gastric emptying: This is how long it takes for food to move through your stomach into the small intestine.
• Small intestinal transit time: The time it takes for food to move through the small intestine.
• Colonic transit time: The time it takes for food to move through your large intestine, including the proximal, distal, and rectosigmoid colon. This part of the digestive process takes the longest.

Here are the average ranges for GI transmit times by segment:

Your digestive system is made up of four main parts:

• GI tract, which includes your:
  • mouth
  • esophagus
  • stomach
  • small intestine
  • large intestine
  • anus
• pancreas
• liver
• gallbladder

This is what happens when you digest food:

As you chew, glands in your mouth release saliva. This digestive liquid contains enzymes that break down the starches in your food. The result is a mushy mass called a bolus that’s easier to swallow.

When you swallow, the food moves down your esophagus — the pipe that connects your mouth to your stomach. A muscular gate called the lower esophageal sphincter opens to let the food move into your stomach.

Acids in your stomach break down the food even more. This produces a mushy mixture of gastric juices and partially digested food called chyme, which moves on to your small intestine.

In your small intestine, your pancreas and liver contribute their own digestive juices to the mix.

Pancreatic juices break down carbohydrates, fats, and proteins. Bile from your gallbladder dissolves fat. Vitamins, other nutrients, and water move through the walls of your small intestine into your bloodstream. The undigested part that remains moves on to your large intestine.

The large intestine absorbs any remaining water and leftover nutrients from the food. The rest becomes solid waste, called stool.

Your rectum stores stool until you’re ready to have a bowel movement.

Some foods may impact the rate at which your body can digest nutrients.

For instance, high fiber fruits and vegetables are rapidly digested. In fact, high fiber foods can help your digestive tract run more efficiently in general.

On the other hand, high protein sources like meat and fish contain more complex molecules that take longer for your body to break down.

Processed, sugary junk foods like candy bars are the quickest to digest. Your body tears through them in hours, quickly leaving you hungry again.

Certain conditions can disrupt digestion and leave you with some unpleasant side effects like heartburn, gas, constipation, or diarrhea. Some of these conditions include:

• acid reflux and gastroesophageal reflux disease (GERD)
• constipation
• diarrhea
• diverticulitis
• inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn’s disease
• irritable bowel syndrome (IBS)
• food intolerances, such as to lactose and gluten
• fecal incontinence

To help keep food moving smoothly through your digestive system and prevent issues like diarrhea and constipation, the United Kingdom’s National Health Service (NHS) recommends the following tips:

• eat at least 30 grams of fiber per day
• eat high fiber foods, such as greens, whole grains, and oats
• eat four or five smaller meals per day instead of three large meals
• drink plenty of fluids to avoid dehydration
• add probiotics to your diet, such as by eating yogurt, kefir, and kimchi
• eat lean protein, such as chicken, fish, turkey, and tofu
• exercise daily
• avoid high fat, greasy, and ultra-processed foods
• limit the amount of spice you eat
• try stress-reducing activities, such as yoga and meditation
• quit smoking, if you smoke
• maintain a moderate body weight

How long does it take for the stomach to empty after a meal?

How quickly your stomach empties after eating depends on the type and amount of food you eat. The average time of gastric emptying is 0 to 6 hours.

Does it take 30 minutes to digest food?

It usually takes longer than 30 minutes to digest food.

What foods take the longest to digest?

High protein foods like meat and fish take the longest time to digest, while processed, sugary foods like candy are the quickest to digest.

Is 2 hours enough to digest food?

Foods may leave your stomach and pass into the small intestine within 2 hours. However, it takes 28 hours on average for food to fully digest.

You might not think much about your digestive system on a daily basis.

However, you’ll know when it’s not working optimally by uncomfortable symptoms like gas, bloating, constipation, and diarrhea.

Watch what you eat and stay active to keep your digestive tract moving smoothly and feel your best.