Fat. In most people, the word invokes images of morbidly obese people or, in a lot of cases, reminds people of their own beer gut/spare tire that they are lugging around on their midsection. Fats were given a negative connotation because of bad science and a big marketing push in the ‘70s where the scientific nutrition community was telling everyone to avoid fats like the plague. The publishing of study after study blaming fats for heart disease, cancer and obesity and the development of low-fat diets continued the trend, and despite the releasing of new information and research and the efforts of many scientists and doctors to re-educate the public about fats, the label of fats as “bad” has stuck. The problem is that fats are not only an essential part of your diet and necessary for many vital bodily functions, but most people tend to replace fats in their diet with processed carbohydrates, which when eaten in excess are an even greater cause of obesity than excess fat intake.
Fats (or “lipids” as they are called in the science world), are used in the body in cell functioning, the creation of cell membranes/walls and as the building blocks and transportation system for hormones throughout the bloodstream. They are also used in the storage of excess energy in the form of adipose tissue (what people commonly think of as fat), which also serves as insulation for the body. This is why they are so important.
In Part One of the Fat Series, we are going to give you a quick science lesson on fats. Fats, or lipids, are molecules comprised of carbon-hydrogen (C-H) chains with a “carboxyl group” (C-O-O-H) on the end that makes the molecule hydrophobic. Yes, that means scared (-phobia) of water (hydro).
When forming a cell membrane, the molecules align themselves with the hydrophobic carboxyl group on the outside to form a wall which water cannot penetrate. This same hydrophobic mechanism allows them to bind hormones, vitamins and minerals and transport them through the bloodstream.
The structure of a fat can take three forms: Saturated, Cis (“same” in Latin) unsaturated and Trans (“across” in Latin) unsaturated.
- A saturated fat has all available spots filled with hydrogen atoms and therefore is extremely stable (hence, they have a high boiling point and are solid at room temperature). Examples include animal fats such as lard, or longer chain vegetable oils like coconut or palm kernel oil.
- Unsaturated fats have open spots and are therefore unstable, which gives them a lower boiling point (hence, they are liquid at room temperature). Most vegetable oils fall in this category, i.e. olive or canola oil.
- The Trans configuration eliminates the kink in the molecule and results in a more stable structure, similar to saturated fats. Almost all Trans fats are manufactured from converted unsaturated vegetable oils. However, one type of Trans fat called vaccenic acid, can be found in nature in products from rudiment animals (animals with multiple stomachs like cows and goats), but these occur in such small amounts that they are negligible.
Now that you know the basic chemistry behind fats, we’ll get into Part Two of The Fat Series next week, which will take a look at unsaturated fats and why we like them.