Social jetlag and obesity - research raises health concerns over 24 hour lifestyles

Humans have a natural body rythm that is kept in syncronisation by the daily succession of daylight and darkness.

Surveys conducted by the Ludwig Maximillian University at Munchen suggest that in Western societies two thirds of the population are burdened with a significant discrepancy between their internal time and the demands imposed by school and work schedules and leisure stress

 In persons who get too little sleep, the perception of hunger is perturbed, often leading to overeating.  Social jetlag shows a significant association with increased body-mass index (BMI

http://www.uni-muenchen.de/aktuelles/news/2012/f-22-12.html

To understand this article it may help to know about the existence of non-imaging ganglion cells in the eye - which sense the blue light associated twilight, and which play a role in melatonin supression with is partly responsible for regulating the human body clock.

We should also be interested in environmental factors that could disturb sleep including

- noise - including aircraft, but more extensively from vehicles.

- artificial light - including poorly directed street lighting, and artificial light with a high blue-end component.