How does the digestion and absorption process of fatty foods in the body proceed? Fatty foods in eaters must be emulsified by emulsifier and then hydrolyzed into glycerol and fatty acids by lipase before they can be absorbed and utilized by the body.

Although adult gastric juice contains a small amount of lipase, there is no fat emulsifier, and adult gastric juice is acidic, which is not conducive to lipase activity, so fat can not be digested in the stomach. Because the milk eaten by infants and young children is emulsified, and the gastric juice of infants and young children is weakly acidic, the fat has already been digested in the stomach of infants and young children.

The main part of the digestion and absorption of lipid food in the body is the small intestine, which is attributed to the fact that the small intestine provides a suitable environment for the digestion and absorption of lipid food.

1. Bile acid salt secreted by the liver and flowing into the small intestine through bile duct is a good emulsifier, which can emulsify and disperse macromolecular lipids in food into fine particles, which not only increases the contact area between lipase and fat, but also promotes the further development of digestive function of the body. Bile acid salt is also an activator of lipase, which can improve the activity of lipase.

2. The digestive juice secreted by pancreas contains a large amount of pancreatic lipase, which is a catalyst for promoting fat hydrolysis.

3. The pH value in the small intestine is weakly alkaline, which is the best place for lipase activity.

After ingesting fatty food, it is emulsified into fat particles by bile acid in the intestine. Under the action of intestinal pancreatic lipase, each lipid molecule is decomposed into one glycerol molecule and three fatty acid molecules, which are absorbed and utilized by the human body. The products of lipase hydrolysis (digestion) are glycerol and fatty acids. Glycerol can directly enter intestinal mucosal cells and be absorbed by the body. Fatty acids are insoluble in water, and can only be absorbed by human body after they combine with bile salts to form water-soluble complexes. Lipids that have just been absorbed into the blood circulate in the body in the form of particles, and people call these fat particles in the blood chylomicrons. The absorbed glycerol and fatty acids can be re-synthesized into new fat in the liver, and combine with protein (apolipoprotein) to form a complex, which enters the blood circulation through blood and lymph and is transported to various parts of the body for utilization.