Do you like noshing on the job? The food you eat at work — whether it’s at the cafeteria, from a vending machine, or in the break room — probably isn’t healthy for you. And those extra calories can add up.

A study of 5,222 workers in the United States found that the foods we eat at work include high amounts of refined grains and sodium and not enough whole grains or fruit.

Stephen Onufrak, an epidemiologist with the Centers for Disease Control and Prevention (CDC), said it’s the first study to look at the food people consume at work.

“The foods people get from work don’t align well with the recommendations in the Dietary Guidelines for Americans,” he said. Onufrak presented the study results at the American Society for Nutrition annual meeting this month in Boston.

According to the research, about a quarter of study participants got food from work at least once per week. The average calories of those foods was nearly 1,300 per week. More than 70 percent of the calories came from free food: leftover birthday cake in the break room, holiday cookies, or other treats.

“With employees spending eight hours a day on average at their place of employment, a lot of people may not be aware of all of the calories they get from food at work, especially from foods they get for free,” Diane Harris, another CDC researcher and study author, told Healthline. “Americans should be concerned because good nutrition is essential to keeping current and future generations healthy.”

Harris noted that seven of the top 10 leading causes of death in the United States are due to chronic conditions such as type 2 diabetes, heart disease, obesity, and certain cancers — all things that can be impacted by healthy eating.

Onufrak hopes that more companies will embrace wellness programs to improve employee health.

Why work food is generally bad food

Sharon Palmer, RDN, a dietitian from California, said people probably know that bad food choices lurk in the workplace.

But even Palmer was surprised to find out that snacking on the job can add up to an extra 1,300 calories a week.

“This can contribute to a slow, gradual weight gain over time,” she told Healthline.

Palmer said that free food is often used as an incentive. She’s toured many high-tech companies in her home state that make it an added work “benefit.”

But if the food options aren’t healthy, there’s not much of an advantage.

“Some employers are noticing weight gain among their employees — almost like the ‘freshman 15’ when they first start working there,” she noted.

She also pointed out that if food’s free, people may be more willing to indulge.

“People psychologically feel like they need to take advantage of the benefit of ‘free food,’” said Palmer. “If they paid for it, they probably wouldn’t be eating as much.”

Not all workplaces promote free food and not all of the free food is unhealthy.

Some workplaces offer more healthful choices but often companies offer processed food in vending machines and decadent coffee drinks that can pack on calories without offering nutrient-rich options.

The growing obesity crisis can have a large cost both to people’s health and workplace productivity.

A 2014 study found that obesity causes absenteeism in the workplace, which costs the United States $8.65 billion annually.

Tips for healthier workplace eating

Want to eat healthier on the job? Palmer said employees can request healthier options.

“If you see doughnut and cookie trays in the break room, ask for fruit baskets instead,” she said.

Another way to promote better eating at work is to start a health committee. There’s a lot of research on the power of nutrition and wellness to reduce costs for employers and increase productivity among employees, which you can use to make your case.

Want to burn off some of those calories on the clock? Go for a walk on your break or see if you can bring in a fitness class.

As always, try to prepare your own meals for work so you know exactly what you’re eating while you are on the clock.

“Mindless eating of unhealthful foods — not even realizing that you’re grabbing a cookie off of a cookie tray at a meeting or sipping on hundreds of calories in your coffee drink or sweetened tea — is the enemy of wellness,” Palmer said.

Not sure if you eat poorly at work? Document what you put in your mouth for one week in a food diary, she suggested.

“You might be surprised at how much you’re eating while at work,” Palmer added.