How Long It Takes To Digest Food, From Beginning To End
Everybody digests food. But what happens from when food enters your mouth to when it exits your body may not be top of mind for most of us. How long does it take for food to digest? And why are some foods more difficult to digest than others?
From your first bite to the trip to the bathroom, we got to the bottom of everything you need to know (and likely more) about the inner workings of your digestive system.
How long does food take to digest?
Once food enters your mouth, it can take between two to six hours to hit your small intestine in a process known as gastric emptying. From there, the food will be digested for between two to six hours before going to your large intestine. This is where the food spends the longest amount of time, as it can take anywhere from 10 to 59 hours to pass, explains nutritionist Mackenzie Burgess, RDN.
"In addition to the macronutrient composition and diversity of your diet and supplements (think prebiotic fibers and targeted probiotics), there is also individual variety from person to person when it comes to GI motility and speed,"* mindbodygreen's Vice President of Scientific Affairs Ashley Jordan Ferira, Ph.D., RDN, explains.
Summary
How long it takes to digest different foods
What you eat also affects how quickly the digestion process happens. Here's what to know about how quickly different macronutrients travel through the body:
Simple carbohydrates
When you've eaten foods like simple carbohydrates (think sugar or white bread), your body can digest them much more quickly, which is why they do not satiate you as well as more nutrient-dense foods that keep your digestive system busy for longer. "In fact digestion of simple or fast carbs starts straight away in your mouth, whereas fiber and other macronutrients remain intact," Ferira explains.
Proteins and fats
Fats and proteins move through your body at a slower rate, increasing the amount of time you feel full. "This is because proteins and fats are complex compounds that require more steps to be broken down," notes Burgess. "Fats, in particular, take longer to digest because they don't dissolve in water, which means an additional substance, bile, is needed for their digestion," she adds.
Fiber
"The fiber content1 of a food impacts how quickly it's digested," explains Burgess. "Foods higher in soluble fiber form a gel-like substance in the stomach, which slows down the digestive process. In contrast, foods high in insoluble fiber speed up the digestive process because they quickly pass unabsorbed into the large intestine, where they add bulk to stool." Both types of fiber are important to consume regularly, explains Ferira.
Summary
How digestion works
You may be surprised to learn that digestion actually begins before you even take your first bite of food. This is called the cephalic phase of digestion and is kicked off by the mere sight or smell (or even thought or taste) of food as your body prepares to eat.
Here's a peek at the role that different parts of the body play in the digestion process:
- Mouth: Once you've taken your first bite of food, the saliva in your mouth both moistens and helps digest food. As Ferira explains, "Along with chewing, your mouth is where digestion, or the breakdown of food into smaller bits, begins. In fact, your mouth (aka oral cavity) features its own unique set of microbes known as the oral microbiome."
- Esophagus: From our mouth, the food, beverages, and supplements we consume journey down the pharynx and esophagus to the stomach, where they are broken down further.
- Stomach: There are unique acidic compounds and protein- and fat-digesting enzymes in the stomach. "Muscular contractions in the stomach also contribute to the digestive process," adds Ferira.
- Small intestine: Your meal, or "bolus of digested food known as chyme," Ferira explains, will then move into the small intestine via the pyloric sphincter, where digestive enzymes (many of which are secreted by the pancreas) and bile from the gallbladder break it into even smaller pieces. These pieces are absorbed from the gut into the bloodstream to be utilized by the entire body. "A unique array of probiotic species reside in the small intestine, also interacting with our dietary inputs," Ferira says. You can expect food to travel through the muscle-lined small intestine for one to five hours depending on what you've eaten.
- Large intestine: Immediately following the small intestine is the large intestine (aka colon), where the gut musculature gradually moves along any remaining digested and undigested compounds. Another unique habitat of gut flora microbiota reside in the large intestine (given that we nourish our body with microbe-friendly foods and supplements). Another important act is achieved in the colon: bulk. While significant amounts of water are absorbed from the gut into the bloodstream in the small intestine, "the final water absorption activity occurs in the colon, to functionally solidify the remaining indigestible components of our diet, creating stool," Ferira explains.
- Rectum: Finally, food reaches the end of the colon. Fiber assists in bulking up the stool that will then exit your body (via the rectum and finally, anus) at the end of your digestive tract.
Summary
Factors that affect digestion speed
Many factors can affect the speed of digestion outside of the foods you're putting into your body, from physical activity to stress. Some of these include:
- Your stress levels
- The types of foods you eat
- How much you eat
- How quickly you eat
- The health of your gut microbiome
- Your exercise routine
- Your thyroid function
- Medications you take
- Your hydration levels
- Your metabolic health
How to improve your digestion
There are plenty of ways to help keep your digestion ticking along smoothly. Here are a few strategies to start with:
Eat plenty of fruits and vegetables
A diet rich in fruits and vegetables will allow digestion to flow more smoothly as these ingredients are naturally rich in fiber. "Fruits and vegetables contain both soluble and insoluble fibers that are important for maintaining a healthy gut," explains Burgess. "Soluble fiber feeds gut bacteria, which then produce substances that can support a healthy gut microbiome2."
Ferira agrees, adding that, "consuming prebiotic fiber regularly directly fuels postbiotic abundance via fermentation processes in the gut. Not to mention the health benefits the wide array of phytonutrients in fruits and vegetables also deliver."
Prioritize omega-3s
Incredibly healthy omega-3 fatty acids (like EPA, DHA, and ALA) are another functional nutrient that can help move food through the body more efficiently. "Omega-3s have been found3 to help maintain the proper balance of good bacteria in your gut and support the integrity of your gut wall," adds Burgess.
What's more, they are "antioxidant and anti-inflammatory powerhouse fats, especially the marine-derived EPA and DHA varieties," Ferira explains.
Exercise
Regular movement and physical activity are great for a number of areas of the body, and digestion just so happens to be one of them. This is because exercise can promote motility in the gut, effectively cutting down on the time it takes for food to move through the body. "Studies show that exercise may improve gut health in many ways," says Burgess.
Take probiotics
If your digestion needs a boost of daily support, adding a targeted gut health supplement like mbg's probiotic+ can be a smart strategy to help ease bloat, promote regularity, and even aid in making the digestion process that much smoother.*
Eat slowly and mindfully
Eating at your computer isn't doing your digestion any favors! Stress has been known to cause you to feel full more quickly, leading to stomach discomfort and even queasiness from slowed digestion.
For this reason, it's important to eat slowly and savor your food so it can move smoothly through your gastrointestinal (GI) tract.
The takeaway
Seeing as digestion is a natural process that everybody completes, it can be useful to understand the ins and outs of what gets things move more smoothly. To aid digestion, focusing on eating a nutrient-dense diet with plenty of fiber. Taking an effective targeted probiotic can also help to move things along, bulk up stool, and support your overall health.*
Merrell Readman is the Associate Food & Health Editor at mindbodygreen. Readman is a Fordham University graduate with a degree in journalism and a minor in film and television. She has covered beauty, health, and well-being throughout her editorial career, and formerly worked at SheFinds. Her byline has also appeared in Women’s Health. In her current role, she writes and edits for the health, movement, and food sections of mindbodygreen. Readman currently lives in New York City.