What is circadian fasting?

The circadian part refers to circadian rhythm, a.k.a. your internal clock that responds to light. The sleep-wake cycle repeats roughly every 24 hours to maximize our body’s resources. Dr. Amy says, "A typical American eats during a 15-hour window, so I suggest starting to slow that down with a 12-hour fast — typically from 7pm to 7am, which has the added benefit of timing the fast with our internal clocks. I call this circadian fasting… I also think circadian fasting is really doable for busy people, because it is so darn easy to remember." She suggests using little changes to tweak your schedule for big results -- we love that!

How is the circadian method different from intermittent fasting (IF)?

Circadian fasting is a less extreme version of standard IF breakdowns. Dr. Amy explains, "There are a few popular IF diets out there. Most of you probably have heard of the 16/8 fast... This type of fasting is immensely popular, but it’s not what I would recommend to start." So if you’re thinking of dabbling in fasting, circadian fasting is a great place to begin. Ultimately, Dr. Amy feels that while intermittent fasting is good, circadian fasting is better.

What are some benefits to circadian fasting?

Fasting gives our bodies a break between dinner and breakfast, so that our systems can rest and not be working late while the rest of the body is sleeping. Most of us can't do our best work in the middle of the night, and that includes our guts. As Dr. Amy puts it, “Good gut bacteria are also in sync with your body’s circadian biology, which makes them more active or less active depending on the time of day." Other benefits to circadian fasting include leveling out insulin levels (which can reduce diabetic risk) and increasing human growth hormone levels (which can aid weight loss and disease prevention).

How do hormones factor into our overall health? And what foods might help with hormone issues & feeling better generally?

Dr. Amy says hormones are part of the Energy Trifecta: "Our hormones, immune system, and gut are closely linked, and it’s very common for them to tip out of balance. The key to boosting your energy (and solving other health issues, to boot) is bringing these three systems back into balance." There's no magic fix, she says: It's about changing what you eat, when you eat, and how you think. Cut out processed foods, reduce your sugar intake, and eat 6 - 8 servings of vegetables a day — adding more plant fiber will do a lot to improve your health.

How does sleep factor into all of this?

Sleep affects more than how tired you are, says Dr. Amy: ”Even just two nights of poor sleep has huge impacts on your insulin regulation, on your thought processes, [and] on your gut health.” You can improve your sleep by improving your habits, particularly when it comes to light and how it affects your circadian cycle. Getting a dose of daylight in the morning tells your brain that it's daytime, kickstarting your metabolism early and helping you sleep better that night. And while screens are hard to avoid in our modern lives, we can turn down the impact in the evening by activating the night shift or blue-light filter mode on our phones. Switch to lower lighting in the evening, and use blackout curtains in your bedroom to block out any light from the world outside. (Or sleep with an eye mask.)

Thanks, Dr. Amy! For more on this topic, find I'm So Effing Tired: A Proven Plan to Beat Burnout, Boost Your Energy, and Reclaim Your Life on Amazon. And to give her full 1-on-1 with Lisa a listen, click here!