Effects of insufficient sleep on health and obesity

If you don't snooze you lose health and gain weight: evidence from a regression discontinuity design
BSG-WP-2015/007

This BSG Working Paper focuses on the effects of insufficient sleep on health and obesity in the US, and suggests that delaying morning work schedules and school start times may substantially improve average sleep duration.

The authors studied the causal effects of sleep on health status and obesity by exploiting the relationship between sunset time and circadian rhythms, and the discontinuities in sunset time created by time-zone boundaries. Using data from the American Time Use Survey, they show that as sunset occurs an hour later on the eastern side of a time-zone boundary, individuals living in counties on this side tend to go to bed later than their opposite counterparts. However, individuals who have to wake up early in the morning because of their work or school start-time schedules cannot compensate and therefore have less sleep.

Using this variation, the authors find that sleep deprivation increases the likelihood of reporting poor health status and the incidence of obesity. Their findings suggest that the higher propensity to eat late in the evening regardless of the time spent eating earlier in the day, higher likelihood of dining out, and lower likelihood of engaging in moderate or intense physical activity, all contribute to an explanation of sleep deprivation having an effect on obesity.

This paper was written in conjunction with BSG Working Paper 008, “Circadian rhythms, sleep and cognitive skills. Evidence from an unsleeping giant.” Together, they analyse the effects of sleep deprivation and the conflict between our biological needs and our social schedules. Both papers highlight the importance of developing a public awareness about the negative effect of sleep deprivation and suggest that reshaping social schedules in ways that promote sleeping may have non-trivial effects on health. While working schedules respond to economic incentives and returns to coordination, their costs in terms of negative effects on health and human capital should not be underestimated.

About the Authors:

  • Osea Giuntella, is a Postdoctoral Research Fellow at the Blavatnik School of Government, University of Oxford
  • Fabrizio Mazzonna, is Assistant Professor in Economics at the University of Lugano