Longer working hours linked to Obesity, finds study

Obesity, the global epidemic , is a modifiable risk factor affecting all age groups. Evidence shows that there is modest association between work stress and obesity.

Researchers have found in a meta analysis that longer working hours were linked with being over weight. The study was published in the journal, International Journal of Obesity 2020.

The present study is a large collaborative study of 19 cohorts from Europe, the US and Australia. Data was collected from Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium or from digital repositories of research data. The studies were chosen according to the availability of working hours and BMI data with the follow up not exceeding 10 years.

There were 122078 participants in the study and were followed up for 4.4 years. Working hours were measured at baseline and categorized as part time for <35 h/week, standard weekly hours (35–40 h, reference), 41–48 h, 49–54 h and ≥55 h/week as long working hours. BMI was calculated as <25as not overweight, 25-29.9 as overweight and 30 or more as obese.

The key points of the study were:

• Of the 61,143 participants without overweight/obesity at baseline, 20.2% had overweight/obesity at follow-up.

• Compared with standard weekly working hours, the age-, sex- and socioeconomic status-adjusted relative risk (RR) of overweight/obesity was 0.95 for part-time work, 1.07 for 41–48 weekly working hours, 1.09 for 49–54 h and 1.17 for long working hours.

• The findings were similar after multi-variable adjustment and in subgroup analyses.

• Long working hours were associated with an excess risk of shift from normal weight to overweight rather than from overweight to obesity.

• Long working hours were not associated with weight loss among participants with obesity.

The authors gave the possible mechanism explaining the association between long working hours and weight gain may be extended periods of sitting, as most of the occupations are sedentary.The other reasons could be lack of exercise and resources, unhealthy lifestyle, and diet. Thus the researchers concluded that there is risk of overweight among individuals who work longer hours. 

for further reading, click the following link: doi: 10.1038/s41366-019-0480-3