Lipids as Long-Term Energy Storage

Long-Term Energy Storage: Lipids

We often think of carbs as our main source of energy, but carbohydrates only serve a short-term purpose.

Our cells can store energy for longer periods of time in the form of lipids. Lipids are a good choice for this because they store more than twice as much energy as carbohydrates, at 9 calories per gram. Carbohydrates store only 4 calories per gram.

How does long-term storage work?

Carbohydrates, like glucose, can either be converted to ATP and used immediately or stored as glycogen in muscles. They are easily and quickly accessible. Carbohydrates can also be converted into lipids for longer storage.

In animals, lipids can be stored in the form of triglycerides within specialized adipose cells. They aren't used for energy until the body starts to run low on, glucose. Lipids are more difficult to break down, which is why many people find it hard to lose body fat.

Lipids

Similar to carbohydrates, one of the main biological functions of lipids is to store energy. Lipids, however, can store about twice as much energy as carbohydrates and therefore, can be asociated with long-term storage. With regard to nutrition, fats contain nine calories per gram while carbohydrates only contain four calories per gram.

Lipids are compounds that are generally insoluble in water. Examples include fatty waxes, oils, and phospholipids.