How Long Does It Take to Digest Food? A Complete Breakdown

As a young child, you might have been discouraged from swallowing gum because it stays in your digestive system for seven years — however, that is simply not true. But it might remain in your system for some time, perhaps even a few days. How come?

While most people think that digestion ends after the food is out of the stomach, the process continues for an extended period in the intestines. How long, exactly? This article will shed light on this question.

The journey through your body: a step-by-step look

In this section, we will look at what happens during digestion step-by-step so you can have a clearer picture of what organs are involved and how.

Mouth to stomach

Digestion, which is essentially the process of breaking down larger particles into smaller ones so our bodies can absorb them, starts in the mouth.

In the mouth, two main things happen: mechanical breaking down of food and chemical digestion aided by saliva. As we chew, the digestive enzymes found in saliva mix with food to start the process, although the impact of those enzymes at this stage is only minor.

After that, the food moves from the mouth to the stomach via the esophagus.

The stomach’s role

In the stomach, again, both mechanical and chemical digestion happen. The mechanical part is aided by the stomach’s muscle and is also called churning; however, during this step, chemical digestion accelerates. In the stomach, the food you consume (bolus at this point) is mixed with stomach acid that breaks it down into chyme.

The normal stomach emptying time is estimated to be around 2–5 hours.

Small intestine: the nutrient absorber

Chemical digestion continues in the small intestine, with the help of the pancreas, which produces digestive enzymes. The small intestine also has another important function: this is where most of the nutrient absorption happens. To be efficient, the small intestine has a vast surface area due to folds, villi, and microvilli.

The normal transit time of the small intestine is estimated to be 2–6 hours.

Large intestine: water and waste

While water and some nutrients are still being absorbed in the large intestine, this is where the feces are formed. Human stool contains various undigested food materials, including dietary fiber.

The normal transit time of the large intestine is the longest, approximately 10–59 hours in total.

How long does it take to digest food?

Although the time it takes for the food to pass through the entire digestive system can vary, research studies estimate it to fall somewhere between 10 and 73 hours in total. The median number of hours is approximately 28 hours. There are slight discrepancies across sources, and overall digestion is highly variable depending on the individual.

How long does it take to digest liquids?

Liquids tend to be digested faster — however, this primarily applies to water and other low-calorie beverages.

For instance, research suggests that in 10 minutes, about 50% of the water ingested will already be out of the stomach. High-caloric drinks tend to stay in the stomach slightly longer than water, with around 50% still remaining in the stomach two hours after drinking. Compared to solids, however, they still leave the stomach faster, as solids are estimated to reach 50% emptying in around 2.5 hours.

What speeds up or slows down digestion?

The time it takes to digest food will also be influenced by several factors, including:

• Physical activity. Exercise can promote a quicker digestive process. “Exercise gets those intestinal muscles moving food along,” explains Dr. Hussain Ahmad, a doctor and consultant practitioner working in a UK-based clinic, whom we reached out to for an expert comment.
• Stress. As added by Dr. Hussain Ahmad, stress may divert blood flow away from digestion, making it slower.
• Individual factors. Each person’s digestive system can vary, meaning that the overall digestion time differs from person to person.
• Digestive diseases and conditions. Health conditions like inflammatory bowel disease, irritable bowel syndrome, food allergies, and GERD may impact digestion times.
• Medications. Certain medications can slow or speed up digestion.

Quick-digesting vs. slow-digesting foods

While digestion is a complex process, and the time it takes to digest food fully will vary greatly from person to person, some nutrients are associated with slower or faster digestion times.

Fiber

Depending on the fiber type, it can either slow down or speed up your digestion. “Soluble fiber absorbs water and creates a gel, which can slow digestion and create a sense of fullness. Insoluble fiber can add bulk and speed digestion,” explained Cheryl Harris, MPH, RD, whom we contacted for her insights.

“The delay also helps support normal blood sugar levels, as food is broken down and absorbed more gradually — this prevents rapid sugar spikes in the bloodstream. Whereas insoluble fiber helps to add bulk to your stool, which helps to support regularity,” adds Hayley Miller, MS, RDN, LD, in her insights for WellnessPulse.

Protein and high-fat food

High-fat and high-protein foods usually take more time to digest. Some forms of protein are considered to be slower to digest than others, notably casein, which is known to absorb slowly. Casein protein is found in milk and milk products.

Simple carbohydrates

Carbohydrates that are made up of simple structures will take less time to digest because they do not need to be broken down as much as complex carbohydrates. Table sugar is considered an example of a simple carbohydrate.

The role of your gut microbiome

Our bodies host a wide range of bacteria, fungi, and other microbes that are essential for digestion. “They help us break down certain types of carbohydrates and fibers that our own enzymes cannot tackle. In doing so, they produce beneficial compounds like short-chain fatty acids, which help maintain the lining of the gut and reduce inflammation,” explains expert Dr. Olalekan Otulana, a GP and physician based in the UK.

An unbalanced gut microbiome can lead to various digestive problems, including irregular bowel movements, while a ‘healthy’ microbial balance may aid the process.

When things go wrong: abnormal digestion times

For this section, Hayley Miller, MS, RDN, LD, gave us her insights regarding abnormal digestion times:

When your digestive system takes longer than normal to process food, it can lead to discomfort — like bloating, nausea, and abdominal pain. If this pattern persists, it may increase the risk of complications such as gastroparesis, a condition where the stomach empties too slowly.

Hayley Miller, MS, RDN, LD

Tips for healthy digestion

Here are some tips for supporting digestion:

1. Try to include foods that are beneficial for gut health, for instance, foods rich in probiotics (e.g., kefir, kimchi, yogurt).
2. Aim for an adequate fiber intake. “Sources of fiber include fruits, vegetables, and whole grains. You should aim for around two cups of fruits and two cups of vegetables daily, along with some whole grains, to help keep your digestive system running smoothly,” advises Hayley Miller, MS, RDN, LD.
3. Drink an adequate amount of water to stay hydrated.
4. Stay physically active, as exercise may help digestion.
5. Consider eating smaller meals more frequently. This could help if you are experiencing certain gastrointestinal symptoms, such as bloating, often.
6. Avoid overly greasy, processed, or high-fat foods.
7. Manage stress through practices like yoga or meditation.

If you are concerned about having frequent gastrointestinal symptoms that may be related to slowed gastrointestinal emptying, it is best to consult your healthcare provider for proper evaluation.

Final thoughts

While stomach emptying happens relatively fast, in around two or five hours, food is not fully digested, and nutrients are not absorbed by then. Food goes through the intestines until the nutrients are absorbed fully, and undigested food material is eliminated from our bodies as feces. This entire journey may take up to 73 hours; however, the median time is estimated to be around 28. You might also find somewhat different numbers in academic literature, depending on the source.

It's best to treat these timings with a grain of salt and have them for general understanding, not as exact rules. Additionally, while digestion time may offer some insights into digestive health, it is definitely not a standalone determinant of it, especially when the ‘normal’ digestion time has a very broad range that can be influenced by many factors.

The exact time it takes to digest food will highly depend on factors such as meal composition and size, your individual metabolism rate, medical conditions, stress, and physical activity levels, just to name a few.

To aid digestion, prioritize high-fiber foods, as they may contribute to normal bowel movements. If you are experiencing any uncomfortable symptoms, consult your healthcare provider for personalized advice.