Intermittent fasting (IF) used as an alternative to continuous energy restriction (CER) supports metabolic health improvements and weight loss in night shift workers, a Monash University-led study (the SWIFt study) has found.
Published in The Lancet’s eBioMedicine, researchers tested the effectiveness of two modified IF strategies, more commonly known as the 5:2 diet, compared with CER on weight loss and improvements in insulin resistance in 250 night shift workers.
For 24 weeks the participants followed a diet of 2100 kJ/d (about 25% of usual dietary intake) for two days of the week (5:2 diet) either on days off/day shift or whilst on night shift and ate their usual diet on the remaining five days. At 24 weeks of following the different interventions, the data was compared to the group following the CER diet.
“Due to their work schedules, night shift workers have little choice but to eat at times of the day normally associated with sleeping, and because of this weight gain and an increased risk of developing type 2 diabetes are recognised consequences of night shift work,” explained Professor Maxine Bonham, from the Department of Nutrition, Dietetics and Food, at Monash’ School of Clinical Sciences.
“The reason we used intermittent fasting was to remove some of the challenges faced by night shift workers who faced limited food choices as a result of their work schedule.”
“By testing the effectiveness of two 5:2 strategies compared with continuous energy restriction on weight loss and improvements in insulin resistance in night shift workers, we were able to understand that just by minimising food intake 1-2 days a week, without changing any other aspect of their diet, we can improve night shift worker health.”
Professor Bonham said that for the first time, researchers have been able to show that the 5:2 diet offers an alternative approach to improving metabolic health, including blood pressure, body weight and insulin resistance. For night shift workers, the approach may be more flexible for their lifestyle.
“Access to food at night can be challenging for night shift workers as often their choices may be limited to take away or vending machines. Interviews with participants from the SWIFt study showed that the IF strategies were both acceptable and provided flexibility around their shift schedules. We did however provide the food for the two days/nights.”
