Night shift work increases risk of obesity/overweight by 23 percent.
Night shift work increases risk of abdominal obesity, which is characterized by visceral fat accumulation in the abdomen and is commonly associated with abnormal metabolic profiles (like insulin resistance), by 35 percent.
Night shift workers between midnight and 5 a.m. showed a pooled estimate odds ratio of 1:32, meaning the odds of obesity/overweight is 1.32 higher for night shift workers compared to non-night shift workers.
Permanent night shift work showed a higher risk of obesity/overweight than rotating shifts, possibly due to daytime environmental hours interrupting proper sleep.
Highest risks were among 10-hour permanent night shifts or 12-hour rotating shifts compared with other night shift work.