Circadian rhythms play a vital role in our health and well-being as it helps in regulating the sleep-wake cycles. Eating on time and sleeping well helps in correcting and resetting the circadian clock. Adolescents, between age 13-19 years, undergo many lifestyle changes when they move from high school to higher secondary school to college/university. Study pressures, eating fast foods, irregular food intake, reduced sleep—all these factors contribute to drastic changes in the circadian rhythms of the body and show their adverse effects later in life.
In India, the school education system puts a higher emphasis on grades than on practical learning, thus encouraging practices like late-night studies and changes in eating and sleeping routines during weekdays and weekends. So how badly are India’s adolescents affected by this? In a recent study, researchers at the Chaudhary Charan Singh University, India, analysed the complex relationship between these lifestyle changes and the disruptions in the circadian cycles among students from classes IX, XII and the first year of college. The study was published in the journal PLoS ONE.
“In India, similar to a few other countries, the self-worth of a student in the middle-income group is determined by academic success and grades, thus increasing students’ pressure to learn,” say the authors of the study.
The study analysed daily eating patterns, sleep, physical activity, and exposure to light among 99 students from two schools in Delhi. Data related to the type of food consumed were captured through photographs using mobile cameras and was used to calculate the calorie intake by taking reference from websites like CalorieKing, MyFitnessPal and the Food and Nutrient Database for Dietary Studies (FNDDS), USA. These images were also used to ascertain the timings of food intake, its quantity and the quality (fast food vs normal food). Data on daily physical activity, sleep and light exposure was captured using motion-sensing watches.
The results found significant differences seen among the three groups of students in their eating patterns and calorie intake. The average eating duration was the highest for class XII students with more than sixteen hours spent from the first to the last meal of the day, resulting in reduced fasting at night and low digestion time. As the students moved out of school, they had a larger exposure to fast food and had higher irregularity and frequency in food consumption. These factors contributed to a higher Body Mass Index (BMI), especially in the class XII students. Weekends were much worse for the three sample sets, with delays in the meal timings observed especially for the class XII and college-going students, compared to weekdays.
Eating patterns among three students groups [Data source]
Most students slept for less than six hours a day as they studied during the night. Those that slept regularly received a considerable amount of light exposure during the day, while those sleeping during the day were less exposed to light. Insufficient sleep in adolescence is known to have a significant impact on the long term health and well being of the individuals.
These results show that as students transition from high school to higher secondary to college, there is a considerable shift in the lifestyle in terms of exposure to fast food, irregular eating habits, reduced night sleep along with reduced night fasting—all leading to circadian cycle disruptions and a higher risk of cardiovascular diseases and obesity in adulthood. The researchers emphasise the need for creating awareness regarding these effects among the general population, including adolescents and their parents.