Music can set the mood for an occasion. But it can also play a part in what we order at a restaurant or buy at the store.

A study published in the Journal of the Academy of Marketing Sciences finds that the volume of ambient music has a systemic effect on consumers' preferences for healthy food versus junk food.

Volume has a direct impact on heart rate. Soft music calms us, making us be more mindful of what we order or buy. Loud music increases stress and heart rate, inspiring a craving for something less nutritionally valuable.

"Restaurants and supermarkets can use ambient music strategically to influence consumer buying behavior," said Dipayan Biswas, Ph.D, marketing professor at the University of South Florida Muma College of Business."

Dr. Biswas conducted the study at a café in Stockholm, Sweden, which played various genres of music in a loop separately at 55 Db and 70 Db. Menu items were coded as healthy and non-healthy and some items as neutral, like coffee and tea.

Over the next several days, researchers found that 20 percent more people ordered the unhealthy foods when exposed to louder music versus the ambient sounds.

55 Db (295 items sold)

• Healthy: 32 percent
• Non-healthy: 42 percent
• Neutral: 26 percent

70 Db (254 items sold)

• Healthy: 25 percent
• Non-healthy: 52 percent
• Neutral: 23 percent

Many studies have looked at décor, lighting and scent as influencers on food sales and decisions. But this is the first study that looked at how volume and sounds can influence a choice.

A pilot study, two field experiments and five lab studies were conducted in total.