Diet Can Improve Alertness and Productivity in Shiftwork

In a new research study by the University of South Australia, researchers have investigated whether altering food intake during the nightshift could optimize how shiftworkers feel during the night and reduce their sleepiness.

Testing the impact of a snack, a meal, or no food at all, the study found that a simple snack was the best choice for maximizing alertness and productivity.

Lead researcher and University of South Australia PhD candidate Charlotte Gupta says the finding has the potential to help thousands of shiftworkers who work during the night.

“In today’s 24/7 economy, working the nightshift is increasingly common, with many industries—health care, aviation, transport, and mining—requiring employees to work around the clock,” Gupta says.

“As a nightshift worker, finding ways to manage your alertness when your body is naturally primed for sleep can be really challenging.

“We know that many nightshift workers eat on-shift to help them stay awake, but until now, no research has shown whether this is good or bad for their health and performance.

“This is the first study to investigate how workers feel and perform after eating different amounts of food.

“The findings will inform the most strategic eating patterns on-shift and can hopefully contribute to more alert and better performing workers.”

In Australia, of the 1.4 million shiftworkers, 15% (or more than 200,000) regularly work a night or evening shift. Working at nighttime conflicts with a person’s internal circadian clock, making it harder to stay focused and awake. Managing fatigue is therefore critical for workplace health and safety.

Over a seven-day simulated shiftwork protocol, the study assessed the impact of three eating conditions (a meal comprising 30% of energy intake over a 24-hour period (eg, a sandwich, muesli bar, and apple); a snack comprising 10% of energy intake (eg, just the muesli bar and apple); and no food intake at all each consumed at 12:30 AM. The 44 participants were randomly split into the three test conditions and were asked to report on their levels of hunger, gut reaction, and sleepiness.

The results showed that while all participants reported increased sleepiness and fatigue, and decreased vigor across the nightshift, consuming a snack reduces the impact of these feelings more so than a meal or no food at all. The snack group also reported having no uncomfortable feelings of fullness as noted by the meal group.

Gupta says the next step in the research is to investigate the different types of snacks and how they affect shiftworkers differently.

“Now that we know that consuming a snack on nightshift will optimize your alertness and performance without any adverse effects, we’re keen to delve more into the types of snacks shiftworkers are eating,” Gupta says.

“Lots of shiftworkers snack multiple times over a nightshift, and understanding the different macronutrient balances is important, especially as many report consuming foods high in fat, such as chips, chocolate, and fast foods.

“We’re keen to assess how people feel and perform after a healthy snack vs a less healthy but potentially more satisfying snack like chocolate or candy.

“Ultimately, the goal is to help Australian shiftworkers on the nightshift to stay alert, be safe, and feel healthy.”

— Source: University of South Australia