https://www.sciencedaily.com/releases/2018/05/180523160058.htm

A study published in the Journal of the Academy of Marketing Sciences finds the volume of ambient music has a systemic effect on consumers' preferences for healthy vs. non-healthy foods. That's because volume is proven to directly impact heart rate and arousal. Softer music has a calming effect, making us more mindful of what we order. This typically results in healthier choices, such as a salad. Louder environments increase stimulation and stress, inspiring diners to crave a greasy cheeseburger and fries instead.

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