Every living organism, be it a bacterium, a reptile, or a person, has adapted to life throughout its development largely due to the ability to assimilate nutrients from the environment. What are the features of food digestion in humans and animals, what are the principles of separate nutrition based on? You will learn about this from our publication.
Digestive system function and age
Different types of food take different times to digest.
At different ages, the functioning of the human digestive tract has its own characteristics, which is most pronounced if we compare infants, older children, and adults. The work of the digestive system begins in the child in the womb. In the second half of intrauterine development, the fetus begins to absorb the so-called amniotic fluid with the nutrients present in it, which are absorbed into the blood in the stomach and intestines, and the secretory cells of the pancreas and stomach already begin to produce a small number of enzymes.
In a newborn baby, all the digestive organs are set up to assimilate the mother's milk. The salivary glands are still poorly developed, and the active production of saliva begins only by 4-5 months of age, but even at this time, its volume is only 10% of that of an adult. The enzymatic activity of saliva is low, but it is sufficient for the casein of milk to be well absorbed.
Infants have a short esophagus and a horizontally located stomach with poorly developed sections, which explains the phenomenon of regurgitation after feeding. In addition, young children have fewer glands in the stomach than an adult, and the acidity of the digestive secretion is lower. The digestive enzyme pepsin in infants is able to process only milk protein. For the digestion of mother's milk, a baby needs about 2-3 hours, and cow's milk - up to 4 hours, which is why the latter is absorbed worse.
By the age of seven, the number of glands in the stomach increases, and the volume of the stomach increases to 1 liter. In children under the age of 10-12 years, there is an intensive absorption of nutrients in the stomach, while in adults this process mostly occurs in the small intestine. The acidity of gastric juice, corresponding to an adult, is achieved by the age of 15 due to an increase in the production of hydrochloric acid. The activity and concentration of digestive enzymes are highest in the period from 20 to 40 years, then it decreases. In men, the concentration of hydrochloric acid is higher than in women, but after 75-80 years, this indicator levels out between the sexes. In old age, both the activity of the secretion of the pancreas and the intensity of absorption of the digested food decrease.
Digestion time of different foods
Here is the time it takes to digest various foods in the stomach of an adult. Knowing it, you can competently build your daily menu and prevent intestinal blockages. The data are summarized in the table below.
| Digestion time in minutes | Products |
| 15-25 | Vegetable or fruit juice Vegetable broths |
| 20-30 | Semi-liquid, low-calorie food: fruit puree, pureed vegetables Grapes Citrus Kiwi Melons and gourds: melon and watermelon |
| 30-40 | Fresh apples, peaches, and pears Sweet cherries and cherries Cucumbers and tomatoes Vegetable salads not seasoned with oil Leafy greens, celery Bell pepper Stewed Spinach and cabbage Most seafood Cod and flounder Egg yolk |
| 45-50 | Stewed or boiled zucchini Cauliflower and Brussels sprouts Young boiled corn Radish and turnip Egg Beet |
| 60 | Potato tubers Jerusalem artichoke Pumpkin Herring Salmon Trout Salmon |
| 90-100 | Low-fat milk Low fat cheese and cottage cheese Yogurt, kefir Rice plain and brown Buckwheat porridge without meat Oatmeal Millet |
| 100-120 | Normal fat cottage cheese Soy and soy products Lentils Pumpkin and sunflower seeds Sesame Carrot Chicken without skin |
| 150-180 | Walnuts Unsalted Unroasted Peanuts Hazelnut Almond Brazilian nut |
| 180-270 | Beef meat Mutton |
| 240-300 | Hard fat cheese Pork Beans Mushrooms Peas |
In terms of speed, food is digested in this order: carbohydrates, proteins, fats. Raw animal proteins are processed much faster than boiled ones. The longer the heat treatment takes, the worse the digestion process goes, which is why a soft-boiled egg will be absorbed faster than a hard-boiled one. This table will help you with the correct design of your menu. For example, it is healthier to eat potatoes with lean fish, chicken with lentil porridge, etc. In addition, if you adhere to the rule that you cannot eat until the stomach is free of food, you can lose extra pounds without strict diets and restore the normal functioning of the gastrointestinal tract.
Also Read: Vegetarianism: history and theory
Separate power supply principles
The ideal option for the stomach and the body as a whole is to consume foods with the same digestion time at one meal, and each subsequent meal should be carried out after the previous portion has been completely absorbed. An inconsistent diet containing dishes with many ingredients is not considered optimal and leads to the cluttering of the intestines and increased putrefaction processes in it, to the accumulation of toxins.
Having eaten food with a certain time of digestion, you must wait until this process is complete, and the stomach and intestines will not be emptied. During this time, the food will have time to go through a full decomposition cycle. Only after this is it allowed to eat foods that are digested slowly, and vice versa. If you do not follow the sequence of eating foods with different digestion times, then fruits, cooked and raw vegetables, starchy and protein foods begin to ferment together. At the same time, gases, acids, and even alcohol molecules are released, indigestion and intestinal obstruction occur.
Separate feeding principles are based on the use of only compatible foods per serving and must be kept for at least 2 hours between meals. The exception is fruits, after which you can eat other food after 20-30 minutes.
An important rule is considered that first of all, it is necessary to eat liquid food, and during and after meals to avoid drinking. Chew food thoroughly, to a consistency close to liquid. Remember that the fewer types of food you mix, the better it is absorbed and the less you will tend to overeat.
Features of digestion in animals
Different animals process food digestion and assimilation in different ways, let's see this with the example of rabbits, birds, dogs, and hamsters.
Rabbits are animals that need a large amount of fiber, and they can eat up to 30 times a day, while young individuals are more voracious, for example, small monthly rabbits can eat up to 55 times a day. The structure of their gastrointestinal tract is also very interesting since the cecum is 7-9 times larger in volume than the stomach. This feature allows for the processing of a huge amount of plant fiber since microorganisms that decompose cellulose live in such a large appendix of rabbits. In rabbits, the acidity of gastric secretions is high, and its production occurs constantly, even at night, and not only during meals. An interesting feature is coprophagia - this is the rabbits eating their nighttime feces, which differs from the daytime. Thanks to this phenomenon, the body of animals receives more B vitamins.
Birds are endowed with a two-chambered stomach, which is divided into two sections. Each performs its own function: in the first, gastric juice is produced, and the second works like a millstone, there are always many small pebbles and grains of sand in it. In terms of time, grains are absorbed the longest - 6-12 hours, processing insects takes 30-60 minutes. In a chicken, for example, grain can be digested for up to a day, and in sparrows, up to 6 hours.
But in ruminants, the digestive system is more complex, and the stomach consists of several chambers at once: a scar, a mesh, a book, and the stomach itself, which is called abomasum. The rumen is the largest part, and in some species, for example, in cows, it can reach incredible volumes - 110-145 liters. Digestion of food is also not complete without regurgitation when food that has entered the rumen again enters the oral cavity for more thorough grinding. It takes up to 4-6 hours to digest the feed.
And what interesting can you say about dogs? It takes them from 6 to 16 hours to fully process the food they have eaten, depending on the type of food. These four-legged friends have a peculiarity that the concentration of acid in the gastric juice will be different depending on what kind of food you offer your pet. The secret will be most acidic when eating meat, less when eating bread. But the strength of the juice, due to a large number of enzymes, is higher when the dog eats bread, and for meat, although the acidity is the highest, there are fewer enzymes in the juice. It is also interesting that dogs produce liquid saliva for bread, and thicker for meat.
Animals with very sensitive digestion are everyone's favorite hamsters, which cannot be fed with anything. For example, soy that gets into the gastrointestinal tract of a hamster can cause ascites disease, and the acid of citrus fruits is harmful to the stomach lining of these animals. Persimmons can cause diarrhea in your hamster, sugary foods often lead to diabetes, and salty foods interfere with kidney function. Vegetables and not very sweet fruits, raw nuts and corn, beans, porridge on the water and even baby food are well absorbed. Interestingly, the teeth of hamsters are devoid of a protective layer of enamel, this is another reason why the animals should not be given sweets. The hamster's stomach accepts raw apples, pears, and carrots well. Also, the animal's digestive enzymes cope with protein food, and every three to four days, the animal can be fed with the protein of a chicken egg, low-fat boiled fish, or beef without salt. It takes 3-4 hours for a hamster to digest food in the digestive system.
It is interesting
The process of digesting food begins already before it enters the stomach since the salivary and digestive glands are included in the work when you are hungry or feel the aroma of a delicious dish or see it. This phenomenon is based on conditioned reflexes.
The salivary glands of a person produce more than 1.5 liters of saliva per day. Incredibly, the average person consumes up to half a ton of food in a year. The total surface area of the small intestine is 250 m 2.
The main percentage of the hormone responsible for joy and high spirits is produced in the stomach, and it is called serotonin. Digestive juices are unable to digest chewing gum, so when it passes through the stomach and intestines, it remains unchanged and can cause constipation or blockage of the intestinal lumen.
0 Comments