Anti-COVID-19 measures threaten our healthy body weight: Changes in sleep and external synchronizers of circadian clocks during confinement

Authors: BAQUERIZO-SEDANO, LUIS - San Ignacio De Loyola University(USIL); CHAQUILA, JOSE - San Ignacio De Loyola University(USIL); AGUILAR, LUIS - San Ignacio De Loyola University(USIL); ORDOVAS, JOSE - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; GONZALEZ-MUNIESA, PEDRO - University Of Navarra; GARAULET, MARTA - Universidad De Murcia

Submitted to: Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/18/2021
Publication Date: 6/25/2021
Citation: Baquerizo-Sedano, L., Chaquila, J.A., Aguilar, L., Ordovas, J.M., Gonzalez-Muniesa, P., Garaulet, M. 2021. Anti-COVID-19 measures threaten our healthy body weight: Changes in sleep and external synchronizers of circadian clocks during confinement. Clinical Nutrition. https://doi.org/10.1016/j.clnu.2021.06.019.
DOI: https://doi.org/10.1016/j.clnu.2021.06.019

Interpretive Summary: The emergency measures adopted due to COVID-19 have created lifestyle changes with potential effects on individuals' health. The disturbances in daily routines due to confinement and remote work have impacted the biological rhythms and energy balance; however, the consequences of these disruptions have not been studied in depth. The objective of this research was to evaluate the impact of 12-week confinement on body weight, considering changes in several external modulators of the biological clock. To further understand this question, investigators at the HNRCA in Boston, collaborating with researchers in Peru and Spain, studied 521 university students to determine their light exposure, sleep patterns, sedentary lifestyle, and eating times. The results support a significant impact of confinement on several external modulators of the biological clock and body weight. Therefore, during this and future pandemics, health-related recommendations must include behavioral recommendations to mitigate the adverse effects on the biological clock.

Technical Abstract: Background & aims: Emergency measures in the face of the recent COVID-19 pandemic have been different among countries, although most have opted for confinement and restrictions on social contact. These measures have generated lifestyle changes with potential effects on individuals' health. The disturbances in daily routines due to confinement and remote work have impacted circadian rhythms and energy balance; however, the consequences of these disruptions have not been studied in depth. The objective was to evaluate the impact of 12-week confinement on body weight, considering changes in several external synchronizers of the biological clock. Methods: The participants, 521 university students (16-35 years), responded to 52 questions oriented to determine light exposure, sleep patterns, sedentary lifestyle, and eating times. Results: We found a reduction in sunlight exposure and sleep duration, an increment in sedentarism and screen exposure, and a delay in the timing of the main meals and sleep in the whole cohort. These behavioral changes were associated with a twofold increase in obesity. Subjects who increased their sedentary hours and shortened their sleep to a higher degree were those who gained more bodyweight. The most influential factors in body weight variation during confinement were sleep duration, physical activity (sedentarism), and light (timing of screen exposure). The mediation model explained 6% of the total body weight variation. Conclusions: Results support a significant impact of confinement on several external synchronizers of the biological clock and on body weight. Health-related recommendations during the pandemic must include behavioral recommendations to mitigate the adverse effects on the biological clock.