Here's how 'social jet-lag' can affect your weight gain and disease risks

A new research has revealed that people with "social jet-lag" or sleeping patterns which differ significantly between work days and rest days likelier to suffer from obesity and diabetes compared to individuals who are up with the lark even at weekends.

The researchers analysed the sleeping patterns and weight of more than 800 people who have been followed for many years as part of the Dunedin Longitudinal Study in New Zealand, the Independent reported.

Lead author Michael Parson said that obesity, as with many complex health problems, is the result of a number of factors and their study suggests that social jet-lag is one of the factors that need to be taken into account.

Parson added that social jet-lag is an under researched but potentially key contributor to why living against people's internal body clock has an impact on their health.

He further said that the research confirms findings from a previous that connected people with more severe social jet-lag to increases in self-reported body mass index body fat, but this is the first study to suggest this difference in sleeping times an also increase the risk for obesity-related disease.

Parson noted that they found that for every two hours of social jet-lag they saw an average increase of about 2.5kg (5lbs) in fat mass among those individuals and they think this relates to the daily rhythm regulating the expression of about 10 per of the body's genes, many of which are involved in fat metabolism.

He explained that it's compatible with the hypothesis and as little as 2 hours of social jet-lag can increase the risk of health biomarkers such as obesity and diabetes.

The researchers suggest that policies on working hours, such as the introduction of flexi-time, could be introduced to reflect the possible health risk for people who have to work against their body clocks.

Terrie Moffitt, a co-author of the study, said that further research that determines this association could help to inform obesity prevention by influencing policies and practices that contribute to social jet-lag, such as work schedules and daylight savings.

The study is published in the International Journal of Obesity.