The Essential Role of Body Fat in Our Health- Part 3

By: Amber Whittemore RD, BSN, MHSc

Fat stores build and maintain our immunity

A robust immune system relies on adequate fat stores to keep us healthy. This is because our adipose tissue houses many of the integral cells involved in our immune response to new and old foreign antigens. Antigens are any substances that cause an immune response in our body, be it a virus, bacterium, infection, or the protein component of certain foods. In this way, our fat stores play an important role in regulating our antibody response! This makes it an essential part of optimizing our immune response to protect us from these foreign antigens. 

One specific way in which our adipose tissue regulates our immune response is through its role in sourcing the body with cytokines in response antigen exposure4,5. Cytokines are a group of proteins released into the bloodstream in response to an invasion of foreign bodies (antigens). These cytokines are closely involved in the induction and coordination of our body’s immune response.

Another key role that adipose tissue plays in terms of regulating our immunity is through storing Memory T Cells4. These are antigen-specific cells that remain in the body after any previous exposures to a foreign antigen have been eliminated6. In essence, they remember previous antigen invaders so that in the event of re-exposure they can respond quickly to the threat. Upon re-exposure, they quickly convert into large amounts of antigen-specific antibodies – providing a rapid immune response.

There is still much to research in terms of how adequate fat stores protect our immunity, but the emerging evidence makes it clear that it plays an essential role in keeping us healthy!

Fat stores ensure we regulate our temperature adequately

Our fat cells are the home to another key player in regulating our health: Gamma Delta T Cells, or gd T cells. Recent research has found that gd cells permanently reside in our adipose tissue and that they are essential for proper temperature regulation5. Their role is to trigger the breakdown of our stored body fat to generate heat in the body to regulate our temperature whenever we are exposed to the cold.

Given that adipose tissue plays this distinctive role in regulating our body temperature, if we drop below the recommended body fat percentage, we are risking impairing our body’s natural ability to regulate our temperature and keep up warm!

The Bottom Line

Our body requires an adequate store of body fat for daily physiological functioning and well-being. Without this, we lose our innate ability to hone energy during rest and movement, regulate our temperature, and have a robust metabolism and immune system.

So, we can disregard the drive to “melt” away as much body fat as possible and instead aim for a healthy amount of adipose tissue to promote our overall health!

We hope you learned something from today’s blog, and don’t hesitate to reach out to a HEC Dietitian if you have any questions or concerns about your own health! Next week we will be diving into the remaining functions that body fat stores play in our health, which includes promoting proper digestion, bone density, organ and reproductive health!


4Jameson, S. C., Lee, Y. J. & Hogquist, K. A. (2015). Innate memory T cells. Advances in Immunology, 126(2015), 173-213. doi:

5Kohlgruber, A. C., Gal-Oz, S. T., LaMarche, N. M., et al. (2018). γδ T cells producing interleukin-17A regulate adipose regulatory T cell homeostasis and thermogenesis. Nature Immunology, 2018, 19(5), 464. doi: 10.1038/s41590-018-0094-2

6Han, S., Zaretsky, A. G., Andrade-Oliveira, V., et al. (2017). White adipose tissue is a reservoir for memory T cells and promotes protective memory response to infection. Immunity, 47(6). doi: