Lunch for her Stafford County Geico co-worker Chiann Hager was also fast food, usually a hamburger and fries or tacos.

Former colleague Rhonda Kenney Hallesy would buy fast food for lunch and also snack on chips all day, “anything salty or vinegary.”

All three changed their ways last year during a study of how workplace support can affect a person’s ability to stick to a low-fat, vegan eating plan.

Not only were they able to give up meat, poultry, eggs and dairy products with what they described as surprising ease, but they also lost weight and improved their overall health.

“Initially, it was very overwhelming,” said Drummond-Thomas, 44, of Fredericksburg. “Cheese was a big one. I thought, ‘How am I going to not eat cheese?’”

Yet the “dramatic difference” Drummond–Thomas felt while eating a low-fat vegan diet meant she usually didn’t miss cheese a bit.

“I didn’t feel bloated. I had more energy,” said Drummond–Thomas. “I just felt a dramatic difference.”

Drummond–Thomas lost more than 20 pounds during the 22-week study of Geico employees and has continued to lose weight by sticking to the eating plan.

Co-worker Hallesy lost more than 30 pounds by following the low-fat vegan eating plan, and her blood pressure dropped from borderline danger zone to the normal range.

The difference from her previous experiences with commercial weight-loss programs, she said, was that she never felt hungry. Her typical lunch these days is red beans and rice or a salad and soup. She mostly snacks on fruits and vegetables.

“It’s very filling,” Hallesy said. “I’d be lying if I said I still didn’t want chips every once in a while. And if I do, I’ll have them. But I don’t want as much of them, and I don’t eat them as often as I used to.”

The recent study of Geico employees is part of an ongoing research project headed by Dr. Neal Barnard, founder of the Physicians Committee for Responsible Medicine in Washington, D.C., and a longtime advocate of the healing power of a healthy diet.