A new study adds to the evidence that maintaining a regular eating schedule is key for preventing obesity.
Eating at irregular times during the weekend may eventually lead to weight gain.
For many, the end of the workweek brings a welcome respite from the rigid scheduling of workdays.
It offers a taste of freedom: a few days of a more fluid schedule or no schedule at all.
A new study, however, finds that a more improvised weekend eating schedule may link to an increase in body mass index (BMI).
The study’s authors refer to people’s weekend diversions from their regular eating schedule as “eating jet lag,” which they suggest may be as physiologically disruptive as the body confusion that can occur when traversing time zones.
The authors analyzed data from 1,106 undergraduate and postgraduate students between the ages of 18 and 25 years who reported their weekend eating schedules during the school year.
The study ran from 2017 to 2019. Each participant also self-reported their height and weight — the two measurements that make up BMI.
The study’s authors believe that this is the first study to focus on the effect on obesity of changes in meal timing between weekdays and weekends.
— Neil Floch MD (@NeilFlochMD) February 1, 2020
From the students’ responses, researchers were able to determine the cohort’s average meal duration during the week and on the weekends, as well as the eating midpoint — halfway between the first and last meal of the day — for both weekdays and weekends.
To calculate an individual’s overall eating jet lag value, they used a simple formula: eating midpoint on weekends minus eating midpoint on weekdays.
It is all in the timing
Eating jet lag may stem from the same sort of conflict between a body’s circadian rhythm and unusual activity as other forms of jet lag — the sleep disruption that travelers experience — and “social jet lag” resulting from unusual weekend sleeping schedules.
As the study authors put it, “The circadian system is comprised by a master clock and a network of peripheral clocks, all of which are organized in a hierarchical manner.”
One of the study authors, Trinitat Cambras of UB’s Department of Biochemistry and Physiology, explains further: “Our biological clock is like a machine and is ready to unchain the same physiological and metabolic response at the same time of the day, every day of the week.”
The importance of the biological clock in nutrition
During the last years researches proved the body understands calories differently depending on the time of the day. Eating late can be related to a higher risk of obesity. According to Maria Izquierdo Pulido, “this difference is related to our biological clock, which organizes our body to understand and metabolize calories consumed during the day”. At night, however, “it gets the body ready for fasting while we sleep”.
“As a result -the researcher continues-, when intake takes place regularly, the circadian clock ensures that the body’s metabolic pathways act to assimilate nutrients. However, when food is taken at an unusual hour, nutrients can act on the molecular machinery of peripheral clocks (outside the brain), altering the schedule and thus, modifying the body’s metabolic functions”.
The new study was carried out on a population of 1,106 young people (aged between eighteen and twenty-two) in Spain and Mexico. Researchers analyzed the relation between the body mass index and the variability in eating timing during weekends compared to the rest of the days. To do so, authors used a new marker that gathers changes in eating times (breakfast, lunch and dinner) at weekends: the eating jet lag, presented for the first time in this study.
Int’l News with additional input by GVS News Desk