Nutrition Science and Everyday Application - beta v 0.1

LIPID TYPES AND STRUCTURES 259
Figure 5.5. 95% of fats in the diet are in the form of triglycerides. Sterols (like cholesterol) make
up about 3% of dietary fat intake and phospholipids make up roughly 2% of dietary fat intake.
The structure of a triglyceride is made up of glycerol and three fatty acids. Glycerol is
the three-carbon backbone of triglycerides, while fatty acids are longer chains of carbon
molecules attached to the glycerol backbone. The “glyceride” in the word “triglyceride” refers
to this glycerol backbone, while the “tri” refers to the fact that there are three fatty acids
attached. Fatty acids are called acids because they have an acid group (−COOH) on one end
of a carbon chain. A monoglyceride contains glycerol with one fatty acid attached, and a
diglyceride contains glycerol with two fatty acids attached.