When (Not) to Eat 0

Posted on 8, January 2018

in Category Tips

When (Not) to Eat/tips We pay so much attention to what, when, and how much to eat, that this week we are examining when we should take a break from eating. There is mounting evidence to suggest that many health benefits can be obtained from a 12-hour overnight fast, including weight loss and increased insulin sensitivity for blood sugar control. This is a type of fasting, or time-restricted feeding may be a simple health solution that translates into sustained weight loss.


An important disclaimer is that any significant changes to your eating habits should be discussed with your primary care provider and the following is not intended to take the place of medical advice. Additionally, extended fasting is not suitable for some populations including pregnancy, childhood, adolescent and teenage years and individuals with health conditions requiring stringent meal and medication timing.


I can recall as a newly minted dietitian advising that it wasn’t “that” you were eating in the evenings that was leading to weight gain, rather more “what” you were eating that had a greater influence. Many rodent studies and human studies are suggesting that perhaps that advice was misguided and if we take a look at the body’s natural circadian clock, there is a reason.


The circadian clock is essentially your body’s internal clock that coordinates all the hormones involved in sleep, blood sugar regulation, immune function and many other metabolic processes. This clock is naturally designed for a 12-hour window, typically consistent with daytime light exposure. Considering the average American averages sleeps less than 7 hours per night, this leaves 17 hours for eating. Mouse studies have indicated that when food consumption (regardless of nutritional content) was restricted to 8- or 12-hour windows, mice lived longer, had lower rates of obesity, lower cholesterol and blood glucose.


There have been some small-scale human studies exploring extended overnight fasts and the results have been promising. Participants achieved weight loss, regulated appetite, decreased markers for inflammation and blood sugar regulation.


Dr. Satchin Panda revolutionized this concept of Circadian Clock, as it pertains to health span and longevity and has a large-scale study going on examining the beneficial effects of overnight fasting. What is most remarkable about his early rodent studies is that mice whose feeding was restricted to 12 hours had lower rates of obesity, despite have a higher-fat diet than mice that were allowed to eat freely for 24 hours.


A promising study examining time-restricted feeding and it’s effects on women diagnosed with breast cancer indicated that women who performed a 13-hour overnight fast improved blood glucose markers and can decrease cancer risk and recurrence rate by 36%.


I do acknowledge that I did not address night or shift work, which is highly correlated with elevated risks for metabolic diseases. The basic principles of time restricted feeding can apply, even though the hours are non-traditional.


Think you’d like to try a 12-hour overnight fast? Here are some Apps to help.

Zero-Fasting Tracker (Apple)

Vora –Fasting Tracker (Android)

Track my Fast (Android)


Here is the research:





About Dr. Panda at the Salk Institute :https://www.salk.edu/scientist/satchidananda-panda/



Interview with Dr. Rhonda Patrick on time-restricted feeding https://www.salk.edu/scientist/satchidananda-panda/