All fat cells have circadian clocks. What does this mean? It means that the function of fat cells is dependent on the time of day. This means that the light signal we put into our eyes matters. Light goes from our eyes to our master time clock in the brain called the suprachiasmatic nucleus (SCN).

The suprachiasmatic nucles (SCN) uses this time input to sync all other clock genes in the body, including those found in fat cells. Fat cells used to be considered simply storage depots of energy for times of scarcity. We now know fat is an endocrine organ, meaning it secretes hormones and chemicals and plays an important role in energy homeostasis. What happens in fat cells when we have a dysfunctional circadian rhythm?

There is an increase in reactive oxygen species (ROS), inflammation, an increase in fat cell size, a decrease in insulin and leptin sensitivity and a decrease in lipolysis. In non-scientific terms, this means the fat cells are likely to get bigger, decrease their ability to burn fat for fuel and become inflamed. This means the ability to burn fat is organized by something independent of what foods you eat.

What things can strengthen our circadian clocks?

The day-night cycle
The 24 hour magnetic flux from the Earth’s core
Timing of meals
Timing of exercise
Timing of certain light exposures to the eyes

When these things are synced, circadian rhythm is strong. When circadian rhythm is strong, the body can burn fat for fuel and produces less reactive oxygen species inflammation. At the most basic level, see the sunrise and allow your home to become dark into the evening as the sun sets.