It’s only natural when we prefer sunny days to “gray” days. There’s so much more to that story. So, I’m offering here a review of Dr. Jack Kruse’s interview on Brad Kearns’ “Breather Show”: www.bradkearns.com/2020/10/23/. ; episode 222, about the physical effects of our 24-hour circadian rhythm cycling.
Dr. Kruse recommends mastering our circadian rhythm with adequate full spectrum light exposure. His conclusions from his findings include: timing when you eat is more important than what you eat, seeing morning sunlight is critical, snacking or eating every 2-3 hours guarantees life-long obesity, a person can lose a massive amount of weight without counting calories, and everyone needs to eat fats for optimal health.
First of all, here’s some technical information which may help. Cortisol surges around 6 AM and decreases around 6 PM. Ghrelin which signals hunger, especially in the morning to the pituitary gland, drops quickly after eating if you’re not obese. Leptin, a fat-storage hormone involved with satiety, is only efficient when the brain and digestion match for an optimal calorie intake. When the leptin effect is compromised by adverse lifestyle practices, you store fat rather than burn it. If you’re sensitive to the effect of melatonin, it will increase during 4 hours of darkness while ghrelin decreases and leptin enters the hypothalamus.
Now for what all of that means.
- As the rising sunlight hits the retina, melatonin is shut off. Adenosine, most effective at sunrise, initiates the release of serotonin and cortisol within 30 minutes after waking for a burst of alertness.
- If sunrise was at 6AM, melatonin is completely shut-off by 7:30.
- Between 9-10AM alertness and sex hormones peak.
- Around 2:30PM muscle coordination is ideal.
- By 3:30PM, optimal reaction times are present.
- Before 5PM, due to optimal protein synthesis, the cardio-vascular system is most efficient, so it would be an excellent time for exercise.
- By 6PM, as the sun sets, the cardio-vascular efficiency drops, and by
6:30 PM the blood pressure begins to rise to compensate.
- As leptin is released from the fat cells, the core body temperature will rise. Agouti, a neuropeptide from the brain signals an increased appetite, decreased metabolism, and decreased energy expenditure.
- For the next 2-3 hours, as leptin is rising, insulin drops, and a fat hormone (adiponectin) drops, signaling adenosine to be released.
- Sleepiness peaks around 10PM when agouti is at its peak. Sleep occurring in darkness causes the release of melatonin with a drop in core temperature.
- The gastro-intestinal tract shuts down around 11:30 PM.
- At midnight, or 2-3 hours after bedtime, leptin signals to burn energy reserves. Yes, we are built to burn fat at night. This will not happen, with sleep apnea, leptin resistance, or having eaten 3-4 hours before bedtime.
With melatonin and leptin sensitivity, the hypothalamus sends messaging for the upgrading and efficiency of the thyroid gland, causing the BMR to rise and the burning off of excess calories. The hypothalamus is responsible for hormonal and metabolic functions such as regulating body temperature, hunger, improved aspects of parenting and attachment behaviors, thirst, fatigue, sleep, and circadian rhythms. Waking between midnight and 3:00 AM may be from insulin spikes after eating a meal less than 3 hours before bedtime, or being exposed to artificial blue light within 1-2 hours before bedtime. If Prolactin, also released during darkness, is deficient, inflammation and a reduced level of immunity occur. Leptin resistance can be a reason why post-menopausal women gain weight that they cannot lose in the gym.
I hope this has given you some ideas on how you might become more “in sync.”