To explain the theory of fat availability, we have to start with a little bit of basic physiology. Specifically, we have to look at how our body fat actually works. The main purpose of our body fat is to serve as an “energy reservoir” for our bodies. In times of caloric excess (overeating) our body fat expands to store energy by one of two processes:
1. Hypertrophy: Fat cells get bigger in size.
2. Hyperplasia: Fat cells multiply in number.
1. Hypertrophy: Fat cells get bigger in size.
2. Hyperplasia: Fat cells multiply in number.
They expand to store energy in the form of triglycerides, to be used later as energy to supply our metabolic demands when energy from food is limited (caloric restriction or dieting). In other words, our body fat has the unique ability to rapidly expand or contract depending on nutritional status (Energy Surplus or Energy Deficit). Free fatty acids (FFAs for short) are released from adipose (fat) tissue when we need energy. Notice, this happens throughout the day even if you’re not dieting; however, it’s elevated when we are fasting, exercising, or in a caloric deficit (dieting). This is a good thing as most of us who are dieting and exercising are doing so because we want to decrease the amount of our body fat!
