This post is a little heavy on the science, so if you’re into it check it out! I will write a summary easier to follow soon ❤️
Our circadian rhythm is generated by clocks that are innate in nature and move about even absent of environment cues, and our clocks influence many different biological processes including neuronal, endocrine, metabolic, and behavioral function. A region in the brain called the suprachiasmatic nuclei (SCN) plays a role in circadian rhythm generation, and recent research has shown that different organisms in the body have different clocks and have their own circadian rhythm, and are linked together in something called the circadian timing system. I found it so interesting that different organs have their own timing system that regulates different functions, like the hepatic clock regulating fasting glycemic control and glucose tolerance. The SCN has shown be influential in sleep wake cycles, which partially determine feeding and fasting behavior, which can synchronize to photic cues (Johnston et al., 2016). Grens (2013), tells us that evidence has shown that when people fall outside of our daily rhythm, people are more likely to suffer from diabetes, obesity, and heart disease. He also tells us that according to current research, it isn’t just a disrupted sleep pattern that can lead to all of these risks, but it is also the timing of food consumption that can lead to chronic disease. The SCN guides the circadian clocks that are found inside of many of our organs, and they are guided by different cues, some as we have seen are guided by light, but some are guided by food intake (Grens, 2013).
I found it so interesting that genetics also plays such a large role in how our individual genetics can play a large role in defining our circadian rhythm, and how we respond individually to different timed environmental cues like light and nutrient timing. For example, for carriers of a certain snp of CLOCK, showed that they had shorter sleep duration, higher plasma ghrelin concentrations, delayed breakfast time, evening preference for food, and less compliance with a Mediterranean diet pattern. This is such useful information for individuals who struggle with sticking to a certain diet, and have difficulty eating at certain times of the day that have shown to be better physiologically. When our circadian rhythm is misaligned, this can cause decreased glucose tolerance, decreased concentrations of satiety hormone leptin, and increased wake time blood pressure. All of these effects can cause increased weight gain and risks for many different metabolic and chronic disease. If people were more aware of the fact that nutrient timing had such a profound impact on their health, I think people would be more viable to change.
One study shows us that timed feeding is a beneficial approach to enhance weight loss and glycemic control in humans, and also diet induced thermogenesis was almost twice as large in the morning than in the evening when the same meal was consumed. This shows us that individuals would work well by understanding that it is important to refrain from late night eating, maintain a fast, and eat the majority of their food intake early in the day (Johnston et al., 2016). Grens, 2013, tells us that the genome is at different states throughout the day, and Johnston et al., (2016), showed us that we are able to burn more of our meal by thermogenesis earlier in the day than later. Today’s society has made it easy to access food at any time of the day, and also presents food at times when the genome says that is time to fast, so when we eat during these times it might lead to increased energy storage, which leads to weight gain and metabolic disorders. Our bodies have adapted to eat during day light hours, and maladapted to eat at night. By opposing these adaptations, we are setting ourselves up for disease, and inappropriate storage of food (Grens et al., 2013).
Two strategies to help combat this issue I think would be to incorporate intermittent fasting, and refrain from eating late at night. According to Zilberter & Zilberter, (2014), late or night time eating was linked to multiple eating bahavior pathologies that led to elevated blood levels of insulin and glucose which showed metabolic syndrome. When late night eating in one study was excluded, and there was a timed eating phase, the subjects ate 244 less kilocalories than the control group that didn’t have a controlled eating time.
Intermittent fasting involves periods of fasting and feeding. Certain days eating will be restricted severely, and some days eating will be as normal. Thom & Lean, (2017), tell us that since weight loss can lead to different unfavorable metabolic changes in the body that make it hard to keep the weight off, these unfavorable changes can be offset by intermittently fasting energy intake to meet weight loss requirements, rather than doing continuous ongoing energy restriction. Intermittent fasting can help with many different metabolic effects, such as promoting ketosis for its appetite suppressing effects and results in involuntary calorie reduction. With the exclusion of late night eating, and possibly skipping BF, weight loss will occur through involuntary calorie restriction (Zilberter & Zilberter, 2014).
Obtaining from eating late at night, will help decrease calorie intake in the individual, and will also help the body regulate proper storage during the times we have adapted to store energy. Intermittent fasting could also help the individual obtain the benefits of fasting, as well as receive involuntary calorie restriction leading to weight loss.
Grens, K. (2013). Out of Sync | The Scientist Magazine®. The Scientist. Retrieved 19 June 2017, from http://www.the-scientist.com/?articles.view/articleNo/37269/title/Out-of-Sync/
Johnston, J., Ordovas, J., Scheer, F., & Turek, F. (2016). Circadian Rhythms, Metabolism, and Chrononutrition in Rodents and Humans. Advances In Nutrition: An International Review Journal, 7(2), 399-406. http://dx.doi.org/10.3945/an.115.010777
Thom, G., & Lean, M. (2017). Is There an Optimal Diet for Weight Management and Metabolic Health?. Gastroenterology, 152(7), 1739-1751. http://dx.doi.org/10.1053/j.gastro.2017.01.056
Zilberter, T., & Zilberter, E. Y. (2014). Breakfast: To Skip or Not to Skip? Frontiers in Public Health, 2, 59. http://doi.org/10.3389/fpubh.2014.00059