Test Your Knowledge of Fats

Fats are an essential part of a healthy diet and contribute to the taste and texture of foods.

Fats are also a major source of energy and a critical component of cells and tissues.

Fats are classified by their length, type of bond between the carbons, and location.

Unsaturated fatty acids are polyunsaturated fatty acids with more than one double bond.

Omega-3 fatty acids are polyunsaturated fatty acids with alpha-linolenic acid, EPA, and DHA.

Omega-6 fatty acids are polyunsaturated fatty acids with linoleic acid and arachidonic acid.

Omega-9 fatty acids are typically monounsaturated fatty acids, and an example would be Oleic acid. These can be made by the human body.

Omega-9s can be found in foods like canola and olive oil, as well as almonds.

Trans fats result from a process called partial hydrogenation.

Partially hydrogenated oils have been largely removed from foods in North America and Europe because trans fats have been associated with coronary heart disease.

When you eat a food like peanut butter, the body goes through a set of steps to digest and absorb the fatty acids.

First of all, triglycerides are hydrophobic. So they form large globules of fat.

Enzymes called lipases in the saliva, stomach, and secreted by the pancreas can break down triglycerides into free fatty acids and monoglycerides.

But working on the surface of a globule is inefficient, so to speed things up, bile salts produced by the liver break the large fat droplet into smaller droplets which increases the surface area for the lipases to work.

Once the triglycerides are broken down into monoglycerides and free fatty acids, these self-assemble into mixed micelles which have a hydrophobic interior and hydrophilic or water loving exterior.

The micelles glide through the watery environment of the intestinal lumen, and reach the enterocytes in the intestinal wall.

Inside the enterocyte, the fatty acids and monoglycerides reassemble into triglycerides, and these get packed into vesicles.

Chylomicrons are large lipoproteins that transport triglycerides and other lipids from the blood to peripheral tissues.

Chylomicrons leave the enterocyte and enter a nearby lymphatic capillary called a lacteal.

From there, the chylomicron floats in the lymph and flows into the thoracic duct, and then gets dumped into the blood.

Once in the blood, the chylomicron releases fatty acids and monoglycerides in peripheral tissues.

After delivering the triglycerides, the chylomicron shrinks in size and eventually gets engulfed by the liver.

Fats play an important role throughout the body and have a huge number of health benefits that vary by the type of fat we eat.

Saturated fat has been linked to negative cardiovascular health effects, whereas polyunsaturated fat and refined carbohydrate have not.