Understand Fats

The food science that centers around fat is simple. Fats are simply chains of carbon molecules bonded with hydrogen molecules and attached to a glycerol molecule. There are three kinds of fat: saturated, monounsaturated, and polyunsaturated. These terms define the type of bonds that the carbon molecules form with one another and with the hydrogen molecules.

Carbon molecules can bond with four other molecules in various formations. In saturated fats, all the carbon molecules are singly bonded to each other and with two hydrogen molecules. In monounsaturated fats, one of the carbon-to-carbon bonds is a double bond without two hydrogen molecules. In polyunsaturated fats, there are two or more double-bonded carbon molecules.

When hydrogen is introduced into a polyunsaturated fat, the hydrogen molecules begin to bond with the double-bonded carbon molecules. If they line up on the same side of the chain, the configuration is called cis. If the hydrogen molecules line up on opposite sides of the chain, the configuration is called trans. Heat and pressure force the hydrogen molecules to line up in the trans configuration.

In the cis configuration, which is the natural form of mono- and polyunsaturated fats, the positioning of the hydrogen molecules makes a kink in the chain. As a result, they cannot pack closely together, so the fat will remain liquid at room temperature. In the trans configuration, the hydrogen molecules pair up on opposite sides of the carbon molecules. This positioning straightens out the chain, so the molecules pack closely together, making a fat that is solid or semisolid at room temperature.

Unlike fiber-filled foods that move quickly through your system, 95 percent of consumed fat is absorbed into your body. This high absorption rate means that almost every bit of fat that you eat stays with you, causing weight gain and a slow metabolism if you eat more than your body can handle.