Clients always appreciate a happy, friendly person taking care of their needs. Not to mention, smiling makes you feel happy as well. So, service with a smile sounds like a great idea, right?

But insisting that employees put on a fake smile all day comes with a price. According to new research conducted at the University of Buffalo, as well as Penn State University, workers who feel like they are being forced to smile are more likely to drink heavily as soon as they’re off the clock.

A study examining individuals who work with the public was published in the Journal of Occupational Health Psychology. Teachers, nurses, and food service workers were among the professions they examined. But this can be applied to many other occupations, such as sales, marketing, or any profession where one is required to deal with the public.

People in these professions often have to force a smile regardless of how they feel. Additionally, their job success often depends on their ability to suppress negative emotions — such as resisting the urge to frown.

Thus, their income also depends on their ability to smile and act as though the customer is always right — even when fielding complaints that are beyond their control or department.

Smiling and acting sensitive to everyone’s needs (while suppressing their own emotions) may yield higher initial sales or better feedback ratings. It may even lead to closing deals from time to time.

But scientific research often calls this “surface acting,” and it has been known to wear down employees and drain willpower. Before you know it, these workers often find themselves leaving work with the urge to drink alcohol as soon as they clock out.

In a press release, Alicia Grandey, professor of psychology at Penn State said, “It wasn’t just feeling badly that makes them reach for a drink. Instead, the more they have to control their negative emotions at work, the less they are able to control their alcohol intake after work.”

This is especially true for people who find themselves in jobs that aren’t personally rewarding for them. For example, while a nurse may find a sense of satisfaction when smiling at patients, a salesperson who is only smiling because he is desperate to close his next deal may feel drained by constantly smiling.

What to Do About It

Whether you are a commercial real estate broker or you work in retail, pay attention to your drinking habits. Acknowledge how forcing a smile is likely to drain you of the mental strength you need to be self-disciplined outside the office.

Simply recognizing the link between the two — and the potential risks involved — could help you make better decisions. Maybe you should skip happy hour with your co-workers after work. Or you could decide to put a limit on how many drinks you consume each week.

If you’re a boss, it is also important to recognize what your employees deal with. Hold conversations about how hard it is to pretend the “customer is always right.” Let your employees know you understand just how draining surface acting is (you most likely were forced to do it yourself in the beginning of your career).

And a little autonomy for your employees could go a long way as well. Rather than yelling at an employee who looks a little grumpy after an interaction, or reprimand someone who rolls their eyes, understand that their interactions may be helping them blow off some steam at work — which might prevent them from drinking too much after work.