» RELATED: Obesity linked to 11 types of cancer as overweight population grows, study says
Why are night workers at risk?
Night workers are often exposed to light at night, which disrupts their circadian rhythm and suppresses the creation of melatonin.
According to the study authors, melatonin plays a big role in regulating hormones, such as insulin, cortisol and leptin.
Suppressing the melatonin can in turn lead to abnormal metabolic profiles, which, as previously mentioned, is associated with abdominal obesity.
Sleep deprivation is also a major mechanism that alters metabolic profiles and increases body weight, authors noted.
Though the cross-sectional meta-analysis has merits, there are some limitations. For example, the review had a high degree of heterogeneity, meaning the populations spanned a multitude of demographics, had varied smoking and drinking habits and more.
Another study limitation is the lack of definition for night shift work — multiple studies used vague vocabulary.
Researchers suggest future studies should focus on large-scale prospective cohort studies, because cross-sectional research such as this one cannot determine cause and effect.
The authors also call on administrators to modify working schedules to avoid prolonged exposure to long-term night shift work.
Read the full study and its methodology, limitations and conclusions at onlinelibrary.wiley.com.