
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
Definition and types of fats
Medical expert of the article
Last reviewed: 04.07.2025
Lipids are important components of plant, animal, and microbial cell membranes. They are slightly soluble in water and soluble in organic solvents such as chloroform or acetone. There are two main groups of lipids, including open-chain and closed-chain molecules. The open-chain lipid compounds are:
- fatty acids;
- triacylglycerides;
- sphingolipids;
- phosphoacylglycerides;
- glycolipids.
Closed-chain lipid compounds are steroids. The main one in this group is cholesterol.
Fats are an important source of energy that meets daily energy needs and also provides energy in cases where:
- there are no other sources of energy, for example during fasting;
- cells are unable to utilize energy reserves, for example, in diabetes;
Main functions of dietary fats
- Source of energy
- Source of essential fatty acids
- Assists in the absorption and transport of fat-soluble vitamins
- Protecting vital organs from damage
- Structural component of cells
Fat reserves also help maintain body temperature and protect the body's organs from injury. In addition, fat facilitates the delivery and absorption of fat-soluble vitamins and affects the structure of food. The high-energy density of fats increases the value of food products in terms of saturation of the body.