SAN DIEGO — A new clinical trial by Salk Institute and UC San Diego Health shows how lifestyle intervention can improve cardiovascular health in shift workers.

According to scientists at Salk Institute, nearly 30% of Americans are considered shift workers, in which the individual must stay awake for two to three hours between 10 p.m. and 5 a.m. for at least 50 days a year.

In collaboration with the San Diego Fire-Rescue Department, scientists from the Salk Institute and UC San Diego Health conducted a clinical trial among 150 firefighters and found that time-restricted eating improved measures of health and wellbeing in firefighters.

Capt. Mark Dombrosky said he became a firefighter to help people.

“Being a part of something bigger than yourself,” Dombrosky said. “Giving back to the community that gave so much to me growing up.”

Dombrosky said being on call for a 24-hour shift is hard on his body. He was part of the clinical trial, and was required to eat only during a 10-hour window without skipping meals for three months. His window to eat was 10 a.m. to 7 p.m.

“Little bit of an early lunch just in case something was going on throughout the day,” he said. “But also if we had a later dinner and then once that 7 o’clock hits, you’re done, it’s water after that. It took probably two months to get used to, but once you got used to it, I can definitely see the benefits of it.”

Dr. Emily Manoogian is one author of the study and said they used the myCircadianClock app to track exactly what firefighters were eating and when.

“If I wanted to take a picture of this, I can write ‘pear and cappuccino’ and then just hit save,” she said, demonstrating how easy the app is. “And now it’s already marked exactly when I had that food and I can track what I’ve had across the day.”

Manoogian said they found that time-restricted eating improved the health and wellbeing of firefighters, like lowering high blood pressure and bad cholesterol. They also reported feeling better emotionally. She said this is not a diet fad, but a lifestyle change.

“They’re able to keep their schedule, they’re able to keep everything else… Pushing those meals in a little bit and allowing for a proper, consistent fast was able to really improve their health,” Manoogian said.

Dombrosky said the biggest benefit he got from time-restricted eating is sleeping better at night, after struggling to feel rested for years. Even though the study is over, he’s still implementing time-restricted eating in his daily life.

“It’s now part of my routine. It’s who I am,” he said.  

Scientists believe the study may also have implications for shift workers in the military and health care, and even for new parents, whose schedules often mimic shift work when caring for a new baby.

To read more in-depth about the study, click here.