Since the 1970’s, fat has been demonized as the primary cause of heart disease. There are so many questions about fat. Is it good? Is it bad? Does it cause heart disease? Does it clog arteries? Is it the cause of our obesity epidemic? These are questions, which were all researched in the 1970’s, and are still being researched by scientists today.
The subject of fat is a complex subject. (Sorry, this too will have a bit of science, but, it’s necessary to explain them. 🙂 ) So, over the next couple of months, we will be talking about the different aspects of fat. I have broken this topic down into a series of six articles:
- Fat-the basics
- Saturated fat
- Unsaturated fat
- Omega fat
- Fats to avoid
What is fat?
Fats and oils fall into a class of nutrient known as “lipids”. By definition, lipids are:
“relatively water-insoluble, organic molecules consisting mostly of carbon, hydrogen, and oxygen atoms. In other words, lipids are hydrophobic (“water fearing”).”
Lipids are typically one of the following
- Oils – These substances are liquid at room temperature – such as olive oil.
- Fats – These substances are solid at room temperature – like butter.
The major categories of lipids include:
- fatty acids – we will be focusing on these types of lipids
- fat soluble vitamins – these vitamins will be discussed later on in the series.
Fatty acids are the most common type of lipid, and found all over your body and in the foods you eat. There are quite literally hundreds of different types of fatty acids, which are normally bound to cholesterol and not found in a “free” form. (1)
Fatty acids are made up of chains of carbon atoms, which comprise the “backbone” of the fatty acid. The length of the chain determines the type, properties and function of the fatty acid. There are 3 chain “lengths” of fatty acids:
- Short chain fatty acids– are made up of less than 8 carbon atoms. These fatty acids have a low melting point and will typically be oils or maybe even gases. These types are formed in the intestine by friendly bacteria, then absorbed through the intestines. (2)
- Medium chain fatty acids – contain between 8 and 12 carbon atoms. An example of this type is coconut oil, which is solid to 76 degrees, then melts. Medium chain acids are sent straight to the liver and used for energy. (2)
- Long chain fatty acids – are comprised of more than 12 carbon atoms. These fatty acids have a high melting point and will normally be solid at room temperature. These types are turned into triglycerides and either used for energy or stored. (2)
Saturated vs Unsaturated Fatty Acids (1)
Fatty acids are broken down further into 2 other groups, based on the chemical bonds between the carbon atoms in the chain. These bonds can either be single or double bonds. These bonds affect the properties and characteristics of the fatty acid.:
- Saturated Fatty Acid – SFA – have all single bonds between the carbon. Because there are no double bonds in the chain, SFA’s are rigid and inflexible, and completely surrounded or SATURATED with hydrogen. This rigid nature makes them quite dense, and, therefore solid at room temperature.
- Unsaturated Fatty Acid – UFA – have one or more double bonds. The existence of double bonds, makes the UFA’s flexible or bendable. It also means there are fewer hydrogen atoms, so the UFA are not surrounded or saturated by hydrogen, therefore, they are UNSATURATED. The flexibility of these acids make them highly unorganized, preventing them from coming together, making them liquid in most cases.
- MonoUnsaturated Fatty Acid – MUFA – have one double bond
- PolyUnsaturated Fatty Acid – PUFA – have two or more double bonds.
Well, I think that’s enough science for one day. In the next issue we will be getting into these fats in more detail, what they do for your body, as well as healthy, whole food sources of each one. In edition, we will talk about which fats are ESSENTIAL FATTY ACIDS (EFA), and explaining TRANS FATTY ACIDS.
I’m happy to see the current trend of people embracing fat. But I also see a dangerous trend, in people demonizing carbs, in much the same way that fat was once demonized. People need to understand that the human body needs all 3 of the macronutrients, protein, carbs and fat. You can’t take one of them out completely, and expect to remain healthy. Eating has to be about more than just losing weight. In my experience, if you focus on health, not weight, the pounds will come off when health improves.
- McGuire, Michelle; Beerman, Kathy A.. Nutritional Sciences: From Fundamentals to Food. Cengage Textbook. Kindle Edition.