Lipid digestion: how are fats digested?
The better knowledge of how lipids or fats are digested by our body can help balance our diet. You should already know that lipid absorption is one of the most complex digestive mechanisms that our digestive system faces on a daily basis. To understand everything, here is precise information on the biology of fat digestion!
What is the role of lipids or fats in the body?
Dietarylipids commonly known as fatsare part of our daily diet. They can be of plant or animal origin. They are naturally present in foods such as fish, meat, cheese, egg yolk, oilseeds, milk, oils, seeds, pastries etc.
They are energy macromolecules (nutrients) that meet many of the body’s needs. Fat is our mainreserve of energy stored in adipose tissue: 1 g of fat provides 9 kcal (a little more than double the caloric intake of proteins and carbohydrates).
Fatty deposits provide energy to cells and contribute to the structure of our nervous, cerebral and hormonal systems. Dietary lipids allow the transport of certainvitamins, play therole of protectionand also serve as a thermal insulatorfor the body.
We often appreciate the texture of food, its good smell and pleasant taste, hence its excessive consumption. But beware, a dietary overload in lipids can cause the development of cardiovascular diseases, overweight or obesity.
How does the fat digestion process work?
As with any food, the lipid digestion phase begins in the mouth. The food is chewed and well impregnated with saliva where it comes into contact with digestive enzymes specially secreted to liquefy lipids: lipases. A gelatinous mixture forms and descends into the stomach through the esophageal canal.
The digestion of lipids and their absorption require that the complex fat molecules thus obtained be broken down into smaller and more assimilable molecules. Then, under the action of gastric lipase, the liquid molecules of lipids are transformed into fatty acid molecules and glycerol molecules. An emulsion is obtained in which the lipid particles are cut into reduced pieces. (1)
This breakdown of lipids takes its course in the duodenum. The digestive system uses bile secretion produced in the liver, but stored in the gallbladder. The combined action of bile and pancreatic enzymes continues the hydrolysis effect (dissolution of fat molecules) of lipids.
This phase accelerates the digestion of triglycerides, which represent the major constituent of dietary lipids. Lipid absorption takes about 10 to 15 minutes through the intestinal villi (cells that line the walls of the small intestine). These walls full of lymphatic vessels absorb fatty acids and glycerol that they carry into the bloodstream and to the membranes of fat cells, where they are stored to be transformed into cellular energy.
Stephen Paul is the lead author and founder of My Health Sponsor. Holder of a diploma in health and well-being coaching with more than 200 articles in the field of health, he makes it a point of honor to offer advice based on reliable information, based on scientific research, and verified by health professionals.