Much research has focused on what to eat and how much to eat. However, emerging research shows increasing evidence that meal timing plays an important role in maintaining the circadian rhythm (a person’s internal clock or night/day cycle) and metabolic health.
Meal timing, also known as chrono-nutrition, focuses on how the body’s circadian rhythm regulates a person’s physical, mental, and emotional cycles. Franz Halberg first proposed the concept of meal timing in relation to circadian rhythm, energy metabolism, and chronic disease in 1967.
A study by Maninder Kaur Ahluwalia in the 2022 edition of Nutrients found that the typical eating window for more than half of the population is approximately fifteen hours a day. Such an extended eating window and short overnight fast contribute to increased food intake, disrupted circadian rhythms, and an increased risk of metabolic disorders.
Research from Jesus Lopez-Minguez et al. in the 2019 edition of Nutrients showed that those who consumed a late lunch (after 3:00 p.m.) had difficulty losing weight compared to those who had an earlier lunch. In addition, those who consumed late dinner (close to 10:00 p.m.) were at risk of hyperglycemia and metabolic syndrome.
On the contrary, a feeding window between eight and ten hours has been found to be beneficial and sustainable for most people. For instance, having breakfast at 8:00 a.m., dinner at 6:00 p.m., and lunch in between leaves a person a ten-hour eating window. If the same individual has their next breakfast after 6:00 a.m. the following morning, they will have fasted twelve hours overnight.
A 2022 study by Emily N. C. Manoogian et al. in Endocrine Reviews indicated hat maintaining a consistent overnight fast of at least twelve hours, which mimics time-restricted eating, can significantly reduce a person’s risk of chronic disease. Participants in this study who consistently followed an eight to ten-hour eating window and fasted at least twelve hours experienced improved body weight, less glucose intolerance and hypertension, and improved metabolism.
Chrono-nutrition boils down to reducing your eating window. In order to start practicing chrono-nutrition, you have to consume your meals earlier in the day so as to extend your overnight fast. This means setting an ideal window for regular mealtimes, including an earlier dinner. In addition, it’s important to keep a regular and healthy sleep pattern since your eating patterns affect your sleep schedule.
Mistimed eating, such as skipping breakfast and eating a late dinner, reflects an eating pattern that may disrupt your circadian rhythm. A misalignment in your circadian rhythm predisposes you to several cardiometabolic risks, such as hyperglycemia and diabetes mellitus, according to Ahmed S. BaHammam and Aljohara S. Almeneessier in an article for the Frontiers in Nutrition journal.
Chrono-nutrition is quite different from intermittent fasting or fasting during the month of Ramadan. Compared to chrono-nutrition, fasting focuses on periods of prolonged food restriction with no regard to the body’s circadian rhythm. Ramadan mainly involves a shift from daytime to nighttime eating and drinking for the consecutive twenty-nine to thirty days of fasting.
According to the Hadith and Quran, the aim of fasting during the month of Ramadan is to attain righteousness. It’s an act of worship for every healthy adult Muslim. In addition, the Hadith highly recommends other voluntary fasting for Muslims throughout the year, such as fasting the six days of Shawwal, Mondays, and Thursdays, among others. These voluntary fasts mimic meal timing patterns during the month of Ramadan.
Chrono-nutrition highlights the importance of aligning what you eat with your circadian rhythm, and eating breakfast and avoiding late-night meals are important components. However, what is most important is choosing an eating approach that will be sustainable for you.
Omolara Funmilayo is the owner of nourishedsupermom.com. She is a certified nutrition and holistic wellness coach. She supports her clients by giving them the tools they need for transformation in health and wellness for themselves and their families.