In this episode I host Dr. Samer Hattar, Chief of the Section on Light and Circadian Rhythms at the National Institute of Mental Health. Dr. Hattar is a world-renowned expert on how viewing light at particular times adjusts our mood, ability to learn, stress and hormone levels, appetite and mental health. We discuss how to determine and use your individual light sensitivity to determine the optimal sleep–wake cycle for you. We also discuss how to combine your light viewing and waking time with the timing of your food intake and exercise in order to maximize mental and physical functioning. Dr. Hattar is credited with co-discovering the neurons in the eye that set our circadian clocks and regulate mood and appetite. He explains why even a small shift in daylight saving time leads to outsized effects on our biology because our cells and circadian clocks integrate across many days. He offers precise tools to rapidly adjust to jet lag, shift work and reset your clock after a late night of work or socializing. This episode is filled with cutting-edge data on the biological mechanisms of human physiology and practical tools for people of all ages. For an up-to-date list of our current sponsors, please visit our website: https://www.hubermanlab.com/sponsors. Previous sponsors mentioned in this podcast episode may no longer be affiliated with us. Social: Instagram - https://www.instagram.com/hubermanlab Twitter - https://twitter.com/hubermanlab Facebook - https://www.facebook.com/hubermanlab Website - https://hubermanlab.com Newsletter - https://hubermanlab.com/neural-network Samer Hattar: Twitter: https://twitter.com/samerhattar Instagram: https://www.instagram.com/samerhattar Wikipedia: https://en.wikipedia.org/wiki/Samer_Hattar Links: Graphical Explanation of Temperature Minimum for Overcoming Jetlag: https://www.instagram.com/tv/CKWiRVJHVwC/ Please note that The Huberman Lab Podcast is distinct from Dr. Huberman's teaching and research roles at Stanford University School of Medicine. The information provided in this show is not medical advice, nor should it be taken or applied as a replacement for medical advice. The Huberman Lab Podcast, its employees, guests and affiliates assume no liability for the application of the information discussed.