The concept of digestion and absorption of food can be complicated and confusing – You’ve eaten your food, but you might be wondering how it’s processed in your body. I would like to clear that up and help you understand what happens – starting with when you eat fat.
Dietary fat is usually made up of triglycerides. A triglyceride is a glycerol molecule (the rectangle) attached to three fatty acids (squiggly lines). The triglyceride has to be broken down by your body to be absorbed before it can be re-built and used for energy or stored.
In our mouth we have an enzyme (molecule that helps reactions take place) that is able to separate some fatty acids off of the glycerol. This process of separation continues in the stomach. It isn’t until the fat reaches the small intestine that a majority of the digestion and absorption takes place by the action of bile salts and enzymes. Bile salts break up fat globules into much smaller emulsion droplets, which increase the surface area where the enzymes can work to break up the triglycerides and create free fatty acids. Plus one fatty acid hangs on to glycerol molecules to make monoglycerides.
These can then form little balls called micelles, which are absorbed by cells lining the intestines. Once inside the cells, the free fatty acids and monoglycerides are reassembled back into triglycerides. Carrier molecules then transport triglycerides throughout the body.
To dive a little deeper, I’ve listed 9 simple steps of fat digestion and absorption: