How long does it take for humans to digest food?

The structure of the digestive system

The digestive system is represented by a set of organs that ensure the absorption of nutrients by the body, which are a source of energy for it, necessary for cell renewal and growth.

The digestive system consists of: the oral cavity, pharynx, esophagus, stomach, small intestine, colon and rectum.

Digestion in the human oral cavity

The process of digestion in the mouth involves grinding food. In this process, energetic processing of food with saliva occurs, interaction between microorganisms and enzymes. After treatment with saliva, some of the substances dissolve and their taste appears. The physiological process of digestion in the oral cavity involves the breakdown of starch into sugars by the amylase enzyme contained in saliva.

Let's follow the action of amylase using an example: while chewing bread for a minute, you can feel a sweet taste. The breakdown of proteins and fats does not occur in the mouth. On average, the digestion process in the human body takes approximately 15-20 seconds.

How long does it take for food to be absorbed in the body?

Food plays a major role in our lives - without it we cannot exist. In addition, our psychological comfort also depends on nutrition. Studies have shown that people who eat a varied diet lose weight much faster than other subjects with the same nutritional content on a boring diet. In addition, it greatly improves your mood. So food is both a physical and psychological factor. But few people think, while chewing a salad, about how long it takes for food to be absorbed in the body .

How it works?

To answer this question, we must, in principle, understand the mechanism of human nutrition. The digestion process begins not in the stomach, but in the oral cavity, where food is ground and ground with teeth, moistened with saliva and enters into chemical reactions with it. In addition, the process of glucose absorption begins in the oral cavity. After this, the food bolus moves through wave-like contractions of the walls along the esophagus into the stomach. This is where the first stage of magic begins - the breakdown of proteins and fats using gastric juice. Food can spend in the stomach from half an hour to 4 hours - it depends on its composition. Fruits and vegetables take the fastest to digest, while fatty meats and mixed heavy meals take the longest to digest. This is why doctors recommend eating fruits and vegetables before meals - so that they do not linger in the stomach for a long time due to heavy components and do not begin to ferment there. If this happens, then the person is likely to experience bloating, belching and other problems with indigestion. Next, the food moves into the intestines. Here, with the help of a dense network of capillaries, the body receives broken down proteins and fats from the digested gruel, and intensive breakdown and absorption of carbohydrates also occurs. At the same time, dietary fiber remains intact and helps remove undigested food particles, preventing them from rotting. Otherwise, a slight general intoxication of the body occurs - acne, lethargy, and fatigue appear. Sometimes people don’t even realize that an intestinal problem is to blame. Food travels this entire path, which ends in front of the large intestine, in 7-8 hours. After this, the food (or rather, what is left of it) accumulates in the large intestine and can wait there for up to 20 hours to be released. So, the answer to the question: how long does it take for food to be absorbed in the body - up to 32 hours. What does this knowledge give us?

Forewarned is forearmed

Knowing the maximum digestion time for various foods, you can optimize your diet and protect yourself from unpleasant health problems. For example, juices or vegetable and fruit decoctions will leave the stomach after 20 minutes, and pasta made from white flour will take almost 3 hours. It turns out that a portion of pasta, washed down with compote or tomato juice, will be there for its legal three hours, during which the juice will simply begin to ferment, since the body temperature is ideal for various bacteria. In general, it is better to eat fatty meat in the first half of the day or at lunch, so that later during sleep the body does not digest food instead of resting. This useful knowledge about how long it takes for food to be absorbed in the body, and actions based on it, will allow you to get rid of excess toxins, for which the skin on your face will thank you by acquiring a healthy color. In addition, activity and vital energy levels will increase. In addition, you will be able to forget about increased gas formation and irregular bowel movements. So it's time to review your diet and menu and take another step towards health and beauty.

Digestive department - stomach

The stomach is the widest part of the digestive tract, has the ability to expand in size, and can accommodate huge amounts of food. As a result of the rhythmic contraction of the muscles of its walls, the process of digestion in the human body begins with thorough mixing of food with gastric juice, which has an acidic environment.

Once a lump of food enters the stomach, it remains there for 3-5 hours, during which time it is subjected to mechanical and chemical treatment. Digestion in the stomach begins with exposure of food to gastric juice and the hydrochloric acid that is present in it, as well as pepsin.

As a result of digestion in the human stomach, proteins are digested with the help of enzymes into low molecular weight peptides and amino acids. The digestion of carbohydrates, which begins in the mouth, stops in the stomach, which is explained by the loss of amylases’ activity in an acidic environment.

The pharynx and esophagus are the beginning of the digestive system

The first area from which the human digestive system begins is the oral cavity. Its function is to crush food and moisten it with saliva produced by large and small salivary glands. Saliva contains an important enzyme for the breakdown of complex carbohydrates. In one day, up to 0.5 liters of saliva are produced in the mouth.

Moistened with saliva and crushed food from the oral cavity enters first the pharynx, then into the esophagus. Many muscles are involved in pushing a food coma, as a rule, their reaction is a reflex. Swallowing is complicated by the fact that the pharynx is close to the trachea. The pharynx and esophagus are separated by the epiglottis, which reacts to the pressure of the tongue muscles by closing the entrance to the larynx, ensuring improved passage. The food lump enters the esophagus, bypassing the respiratory tract.

The muscular tube between the larynx and stomach, 22-30 cm long, is called the esophagus. If it is in a calm state, a gap is visible. The food does not fall in it, but thanks to the wave-like, contracting movements of the walls, it moves smoothly. The esophagus and stomach are connected to each other through an opening in the diaphragm. In this place there is a gateway (muscular sphincter) that allows food to enter the stomach. After this, the valve closes immediately, preventing the backflow of acidic gastric contents.

Digestion in the stomach cavity

The process of digestion in the human body occurs under the influence of gastric juice containing lipase, which is capable of breaking down fats. In this case, great importance is given to the hydrochloric acid of gastric juice. Under the influence of hydrochloric acid, the activity of enzymes increases, denaturation and swelling of proteins is caused, and a bactericidal effect is exerted.

The physiology of digestion in the stomach is that food enriched with carbohydrates, which remains in the stomach for about two hours, undergoes an evacuation process faster than food containing proteins or fats, which lingers in the stomach for 8-10 hours.

Food that is mixed with gastric juice and partially digested, being in a liquid or semi-liquid consistency, passes into the small intestine in small portions at simultaneous intervals. In which department does the digestion process still take place in the human body?

Table - how much food is digested in the human stomach

Digestion - small intestine

Digestion in the small intestine, into which the bolus of food enters from the stomach, has the most important place, from the point of view of the biochemistry of the absorption of substances.

In this section, the intestinal juice consists of an alkaline environment due to the arrival of bile, pancreatic juice and secretions of the intestinal walls into the small intestine. The digestive process in the small intestine does not go quickly for everyone. This is facilitated by the presence of an insufficient amount of the lactase enzyme, which hydrolyzes milk sugar, which is associated with the indigestibility of whole milk. During the digestion process, more than 20 enzymes are consumed in this part of the human body, for example, peptidases, nucleases, amylase, lactase, sucrose, etc.

The activity of this process in the small intestine depends on the three intersecting sections of which it consists - the duodenum, jejunum and ileum. Bile formed in the liver enters the duodenum. Here food is digested thanks to the pancreatic juice and bile that act on it. Pancreatic juice, which is a colorless liquid, contains enzymes that promote the breakdown of proteins and polypeptides: trypsin, chymotrypsin, elastase, carboxypeptidase and aminopeptidase.

The way of the apple: what happens to food when it enters our body - Meduza

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Digestion is a complex process (according to some sources, it lasts more than 50 hours).

Food needs to travel a long way (about 9 meters) to provide the body with energy and all the necessary nutrients. And along the way, anything happens - food is broken down, sorted and processed.

Together we tell you how the digestive system works and what happens to food at each stage.

Yes, as soon as a piece of food, for example an apple, ends up in your mouth, the salivary glands located there begin to actively secrete saliva. It envelops food, making it softer and more uniform.

In addition, saliva contains enzymes - they help break down nutrients into simple compounds (in the mouth this begins to happen with fats and carbohydrates). Sometimes saliva is produced even before a person starts eating.

It's all about the nerve endings that connect the central nervous system with the digestive system. For example, when a person sees or smells an appetizing dish, his brain sends a signal that causes the salivary glands to “get ready” for food and secrete saliva.

Also no less actively involved in the process are the teeth, which grind food, and the tongue, which mixes it with saliva. And thanks to receptors on the surface of the tongue, the brain recognizes and distinguishes the taste of the food we eat.

Chopped, soft food (bolus) can now be swallowed. This is where the tongue (again) and the epiglottis come into play. The first pushes food further along the digestive tract, and the second prevents it from entering the respiratory tract.

Next, the food enters the esophagus, a tube that connects the mouth and stomach. The muscles in the wall of the esophagus, contracting, move the apple further.

These wave-like contractions are called peristalsis, and they occur not only in the esophagus, but also in the stomach and intestines. If everything is normal, a person does not feel these waves - our digestive tract works autonomously.

When the bolus reaches the lower part of the esophagus, the sphincter (also known as the valve that separates the esophagus from the stomach) relaxes and food enters the stomach.

There, thanks to active and powerful contractions of the stomach muscles, food is crushed even more and mixed with digestive (stomach) juice.

It consists of hydrochloric acid, water and such an important enzyme as pepsin, which is responsible for the breakdown of proteins. At the same time, the caustic gastric juice does not harm the stomach in any way - its walls are covered with a reliable protective layer.

As a result of all manipulations, chyme is formed - this is partially digested food, more liquid than solid.

When the chyme is thoroughly saturated with digestive juice, waves of muscle contractions propel it through another valve (pyloric sphincter) into the small intestine, namely at its very beginning - the duodenum.

There, digestive juices come into play, which are produced by the pancreas, liver and gall bladder. The duodenum produces a large amount of mucus to protect its walls from the acids contained in the chyme.

The pancreas produces some hormones (including insulin), as well as amylase, lipases and proteases - enzymes that break down carbohydrates, fats and proteins. The liver synthesizes bile, which helps absorb fatty acids.

Bile ducts carry bile from the liver to the gallbladder (where it is stored) or the duodenum (where it is used). But this, of course, is not the only function of the liver - in its laboratory important chemicals are produced, thanks to which our body functions.

For example, it converts amino acids into each other, synthesizes various fats and stores vitamins and carbohydrates (in the form of glycogen). In addition, the liver neutralizes dangerous and harmful substances.

Just in the small intestine. Through millions of tiny villi that form the walls of the intestine, nutrients enter the bloodstream (fat-soluble substances are first absorbed into the lymph and only then enter the bloodstream).

The blood carries them throughout the body, for example, carrying simple sugars, amino acids, glycerol, some vitamins and salts to the liver, which stores, processes them and, when necessary, delivers them to where they are needed. The main absorption of water occurs there, in the small intestine.

What remains of food when it passes through the rest of the intestine—the jejunum and ileum—is a mixture of water, electrolytes, and various undigested elements (such as plant fibers). All this passes into the large intestine.

Yes. Bacteria in the colon help break down remaining nutrients and also synthesize some vitamin K. There, water is absorbed from leftover food and feces are formed, which then move to the last part of the intestine - the rectum. As a result of muscle contractions, bowel movement occurs.

The digestion process requires a lot of energy. The body spends approximately 10% of all calories from carbohydrates and proteins to ensure that food travels such a long way and the beneficial substances it contains are absorbed.

Sometimes disruptions occur in the digestive system: the stomach hurts, bloating, cramps (painful contractions of the intestines) occur, and stool becomes irregular. In such cases, an antispasmodic can help.

For example, the drug “Neobutin®”, together with the manufacturer of which we made this material.

"Neobutin®" acts throughout the gastrointestinal tract and regulates the activity of neurons - due to this, spasms that cause pain and bloating disappear, and intestinal motility is restored - and, as a result, stool becomes regular again.

There are contraindications, it is necessary to consult a specialist.

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Source: https://meduza.io/slides/put-yabloka-chto-proishodit-s-edoy-kogda-ona-popadaet-k-nam-v-organizm

Role of the liver

An important role in the process of digestion in the human body (we will briefly mention this) is played by the liver, in which bile is formed. The peculiarity of the digestive process in the small intestine is due to the assistance of bile in emulsifying fats, absorbing triglycerides, activating lipase, also helps stimulate peristalsis, inactivate pepsin in the duodenum, has a bactericidal and bacteriostatic effect, increases hydrolysis and absorption of proteins and carbohydrates.

Bile does not contain digestive enzymes, but is important in the dissolution and absorption of fats and fat-soluble vitamins. If bile is not produced enough or is secreted into the intestines, then the processes of digestion and absorption of fats are disrupted, as well as an increase in their excretion in their original form with feces.

What happens in the absence of a gallbladder?

The person is left without the so-called small sac, in which bile was previously deposited “in reserve.”

Bile is needed in the duodenum only if there is food in it. And this is not a constant process, only during the period after eating. After some time, the duodenum is emptied. Accordingly, the need for bile disappears.

However, the work of the liver does not stop there; it continues to produce bile. It is for this purpose that nature created the gallbladder, so that the bile secreted in the intervals between meals does not deteriorate and is stored until the need for it arises.

And here the question arises about the absence of this “bile storage”. As it turns out, a person can do without a gallbladder. If the operation is performed on time and other diseases associated with the digestive organs are not provoked, then the absence of a gallbladder in the body is easily tolerated. The timing of the digestion process in the human body is of interest to many.

After surgery, bile can only be stored in the bile ducts. After bile is produced by liver cells, it is released into the ducts, from where it is easily and continuously sent to the duodenum. Moreover, this does not depend on whether the food is taken or not. It follows that after the gallbladder has been removed, food must be taken frequently and in small portions for the first time. This is explained by the fact that there is not enough bile to process large portions of bile. After all, there is no longer a place for its accumulation, but it enters the intestine continuously, albeit in small quantities.

It often takes time for the body to learn to function without a gallbladder and to find the necessary place to store bile. This is how the digestion process works in the human body without a gallbladder.

Digestive section - large intestine

The remains of undigested food move into the large intestine and remain there for approximately 10 to 15 hours. Here the following digestive processes take place in the intestines: absorption of water and microbial metabolization of nutrients.

In the digestion that occurs in the large intestine, food ballast substances, which include indigestible biochemical components: fiber, hemicellulose, lignin, gums, resins, waxes, play a huge role.

The structure of food affects the speed of absorption in the small intestine and the time of movement through the gastrointestinal tract.

Some of the dietary fiber that is not broken down by enzymes belonging to the gastrointestinal tract is destroyed by microflora.

The large intestine is the place of formation of feces, which includes: undigested food debris, mucus, dead cells of the mucous membrane and microbes that continuously multiply in the intestines and which cause the processes of fermentation and gas formation. How long does the digestion process in the human body last? This is a common question.