How long does it take to digest? Optimizing and understanding your digestive system isn’t just on your plate!

The duration of digestion depends on the course of the digestive process, at each stage in the body.

Contrary to what one might believe, digestion does not begin in the stomach, but in the mouth!

Chewing , an essential preliminary step, is often neglected. However, it is the act of chewing that allows food to be crushed into small pieces, thus facilitating their passage through the digestive tract (and the work to come).

Chewing stimulates the production of saliva, which is composed of enzymes responsible for ensuring the initial breakdown of carbohydrates. In other words, chewing well already means digesting and giving a boost to the digestive system.

☝️Did you know? The salivary flow rate (amount of saliva produced) is between 0.5 and 1.5 liters per day, depending on our eating habits!

Another advantage of chewing: taking the time to savor your food helps you to better sense its flavors, or even reduce portions. By focusing our attention on our sensations, satiety is easier to recognize. 

Once chewed, food moves to the stomach, where digestion takes a more “chemical” turn.

➡️ Gastric juices (composed mainly of hydrochloric acid and pepsin) , are responsible for disintegrating proteins into amino acids. Food remains in the stomach on average between 2 and 4 hours, depending on its nature and composition.

For example, a rare steak covered in cheese (protein and fat) will take much longer to digest than a bowl of soup (mainly water, fiber and carbohydrates).

During this time, the food is transformed into chyme, a kind of paste with a semi-liquid texture that facilitates the rest of the process. The length of time it stays in the stomach varies depending on the quantity and nature of the food ingested, but also on how quickly you ate!

After the stomach, food enters the small intestine, where the most important step takes place: nutrient absorption .

Carbohydrates, proteins, fats, as well as vitamins and minerals are broken down and assimilated by the body:

➡️ Lipids are broken down into fatty acids by bile produced by the liver and pancreatic enzymes;

➡️ Proteins are digested by trypsin and endo and exopeptidases , then absorbed and transported by the blood to organs and tissues, depending on their functions (structural role in collagen, hormonal role in insulin, transport role in lipoproteins, etc.);

➡️ Carbohydrates are transformed into glucose (the body's favorite fuel!) fructose and/or galactose, then absorbed into the blood.

The passage of food through the small intestine can take between 4 and 6 hours. Here, the duration of digestion is determined by the composition of the food ingested.

Logically, poor absorption can lead to deficiencies in certain nutrients.

Beyond the physiological stages, the duration of digestion depends on many factors, hence the complexity of the subject!

Not all foods are equal when it comes to digestion: partly because of their composition, and partly because of whether they are eaten in isolation or combined with others!

➡️ Proteins , such as meat or fish, require extra effort from the stomach. The breakdown of proteins can take up to 4 hours;

➡️ Carbohydrates : In general, carbohydrates are rapidly absorbed, especially when consumed alone outside of meals.

Foods high in fructose (such as fruits) and whose Glycemic Index is high are the fastest to digest. Foods with a low Glycemic Index (low GI) such as whole grains are digested more slowly and provide a feeling of satiety over a longer period of time ;

➡️ Lipids , although essential to our body, slow down the digestive process by staying in the stomach longer. A meal rich in fat like a pizza will take longer to digest than a mixed salad with nuts and cheese!

As mentioned above, the speed at which you eat can influence how long it takes to digest.

A meal swallowed in a few minutes puts more pressure on the stomach: the pieces of food are insufficiently chewed and require more effort to be digested.

Conversely, taking your time to enjoy your meal allows salivary enzymes to begin the work of breaking down the food, making it easier to digest in the stomach.

☝️In terms of eating habits, meal times also affect digestion time! Unstructured meals eaten late in the evening tend to disrupt hunger and satiety signals.

A 2022 study, published in the journal Cell Metabolism, found that late and nighttime eating is associated with impaired digestive function, decreased satiety, and an increased risk of weight gain.

Water helps lubricate the passage of food through the intestine and softens stools, preventing the risk of constipation.

☝️ A word of caution : drinking too much water during meals can dilute digestive juices and slow down the digestion process. This statement is also valid for athletes! Intense physical activity can lead to increased loss of essential minerals (magnesium, potassium, sodium, etc.).

To counteract the effects of a session or periods of extreme heat, opt for a drink rich in electrolytes and vitamins . Homemade version: a large glass of water with lemon juice, a dash of honey and Himalayan pink salt, appreciated for its richness in minerals.

✅ Team advice: drink throughout the day to maintain sufficient hydration, and in small sips during your sports sessions!

Slow digestion, fast digestion: do you know how to identify your typical profile? Knowing this allows you to act on the levers that influence the duration of digestion !

Slow digestion is generally manifested by feelings of heaviness, bloating several hours after meals, irregular bowel movements with episodes of constipation.

Common causes of slow digestion time :

➡️ Aside from proven disorders, the most common cause is diet! Excess fat and processed foods, combined with limited hydration and insufficient fiber intake, lengthen digestion time.

Difficult digestion is not an end in itself: here are some courses of action and solutions to affect the duration of digestion and facilitate its process.

This rule seems basic, but following regular meal times influences a large number of physiological mechanisms, including:

• Synchronizing the body's digestive processes;

• Regulation of blood sugar;

• The production of leptin and ghrelin, hormones that affect feelings of hunger and satiety

☝️ Did you know? According to the traditional Ayurvedic approach, digestive capacity varies according to the time of day and individuals. Indians consider that the “digestive fire” is at its peak between 12 and 2 p.m., the time of the main meal.

✅ Our advice : avoid skipping meals, limit snacking, and organize your schedule so that you eat at the same times.

Good hydration throughout the day is essential for intestinal transit: water facilitates the passage of food through the digestive system and prevents the risk of constipation, acting directly on the duration of digestion.

✅ Like any wellness advice, only the dose makes the poison: excess water intake should be avoided, otherwise it will lead to the dilution of body fluids, and with it, hinder the proper assimilation of nutrients.

Certain foods such as fried foods, spicy dishes, or dairy products (for those who are intolerant) can slow digestion and cause digestive discomfort.

✅ Our advice : if you can't identify the foods causing your digestive discomfort, write down your meals for a few days, then eliminate certain food groups one by one to identify the culprits!

Stress is one of the factors that influences the digestive process: for some, it shortens the duration of digestion, for others, it lengthens it!

✅ Our advice : adopt routines that promote relaxation every day! Practices from Chinese and Indian medicine emphasize the regulation of the nervous system through movement and breathing : pranayama, qi gong, yoga, meditation, mindful walking, etc. This type of technique activates the parasympathetic system and helps reduce stress levels, facilitating digestion at the same time.

C ertain adaptogenic plants can support stress regulation, such as Ashwagandha, from the Indian pharmacopoeia. Appreciated for its benefits on stress and mood regulation, it will be the ally of anxious profiles prone to digestive discomfort!

An Ashwagandha cure therefore acts indirectly on the digestive sphere by rebalancing different biological mechanisms, while helping you to be more relaxed. 😎

Also read: probiotics and flat stomach, fact or fiction?

Digestion is indeed a complex process influenced by several factors, from the nature of the food to eating habits. The secret? Adopt reflexes to support your digestion, and regain overall well-being.