Those dining in well-lit rooms are about 16-24 per cent more likely to order healthy foods than those in dimly lit rooms, researchers said.
"We feel more alert in brighter rooms and therefore tend to make more healthful, forward-thinking decisions," said Dipayan Biswas from University of South Florida in the US.
Researchers surveyed 160 restaurant patrons at four casual chain restaurant locations.
Half of those diners, who were seated in brighter rooms, were more likely to choose healthier options (such as grilled/baked fish, vegetables or white meat) over relatively unhealthy items (such as fried food or dessert).
More From This Section
Follow-up studies showed that when diners' alertness was increased with the use of a caffeine placebo or by simply giving a prompt to be alert, those in dimly lit rooms were just as likely as their peers in brightly lit rooms to make more healthful food choices, researchers said.
From this, they suggest that the main reason that we make healthier choices in well-lit spaces is because we feel more alert.
Doing what you can to make yourself feel alert is the best way to avoid overindulging when "dining-in-the-dark,", according to Brian Wansink from Cornell University in the US.