Snacking better for nights-shifts workers than traditional meals, study suggests

The finding could help millions of shift workers who work during the night.

Laura Townsend
14 August 2019

A snack was shown to reduce the impact of sleepiness and fatigue.

In a study conducted by the University of South Australia, researchers found that a simple snack was the best choice for maximising alertness and productivity.


Researchers investigated whether altering food intake during the nightshift could optimise how shift workers feel during the night and reduce their sleepiness.

Over a 7-day simulated shift work protocol, the study assessed the impact of three eating conditions (a meal comprising 30% of energy intake over a 24-hour period (for example, a sandwich, muesli bar, and apple), a snack comprising 10% of energy intake (for example, 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.

All participants reported increased sleepiness and fatigue and decreased vigour across the nightshift; consuming a snack greater reduced the impact of these feelings than a meal or no food at all; no uncomfortable feelings of fullness were noted by the snack group unlike the full meal group.


The lead researcher, UniSA PhD candidate Charlotte Gupta, said the finding has the potential to help thousands of shift workers who work during the night.

Snacks optimise alertness and performance.

“As a nightshift worker, finding ways to manage your alertness when your body is naturally primed for sleep can be really challenging,” Gupta stated. “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, 15% of 1.4 million shift workers regularly work a night or evening shift; working at night makes it harder to stay focused and awake as it conflicts with a person’s internal circadian clock. Therefore, it’s critical for workplace health and safety to manage fatigue.

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


“We’re keen to assess how people feel and perform after a healthy snack versus a less-healthy, but potentially more satisfying snack like chocolate or lollies. Ultimately, the goal is to help Australian shift workers on the nightshift to stay alert, be safe, and feel healthy.”

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