On a warm and sunny day, Diane Roybal stood outside her brick home in southwest Denver. She’s 69, with brown hair, a warm smile and is battling breast cancer.

“I stay positive and I’m beating it. I’m going to beat it,” she said. “I do everything I can for my body to make sure that it has what it needs to beat it.”

Roybal said her last PET scan was clear, and she has to keep taking care of herself for the rest of her life in order to help avoid a relapse. That includes eating right, avoiding preservatives and additives, going for heart-healthy foods, vegetables, “and good protein, too, to give me energy and stuff.”

She gets special assistance with that diet from people across town in north Denver, in a gleaming, large stainless steel kitchen operated by a nonprofit called Project Angel Heart.

It’s a busy beehive of activity as a small army of volunteers stirs up hundreds of packages for delivery. On a recent day, a savory breakfast bowl, with salsa roja, rice and zucchini were on the menu.

“If I can make one person’s day better, then I’ve done a good job,” said volunteer Jane Garmyn, a retired neonatal nurse from Westminster. “And here I get to make 1,700, 1,800 people a week better.”

Project Angel Heart doesn’t just provide vast volumes of food, at a rate of 750,000 meals last year. These are medically tailored to the specific dietary needs of those living with serious illnesses.

“It does save lives. I believe that it does,” Garmyn said. “We did a study years ago about how feeding people the right food keeps them out of the hospital, keeps them well so that they can do other things.”

Owen Ryan, CEO and president of Project Angel Heart, said the idea is that for a lot of health conditions, especially serious ones, if you return to eating the way you did before you got sick “your medicine, your treatment plan is only going to be so effective.”

He used the example of kidney disease, where patients need to seriously limit eating certain foods.

“You can’t have tomato. There’s certain potassium, phosphorus things you really have to avoid. That’s tough for people to do at home when they get that serious diagnosis,” he said. “They don’t know what to do, they don’t know how to change their food.”

That’s where Project Angel Heart steps in.

“So I like to say that when doctors prescribe a specific diet, we fill the fridge,” Ryan said.

Adhering to the idea of food as medicine is a growing trend, said Dr. Wendolyn Gozansky, a researcher with Kaiser Permanente Colorado.

Chronic conditions drive the majority of health care costs, with one in five dollars attributable to unhealthy diets, said Gozansky, vice president and chief quality officer for the Colorado Permanente Medical Group.

“The bottom line is that food can and should be used as an intervention to improve people’s health, and we need more research in this area,” she said, noting, the current research is “incredibly promising.”

She said most people understand the importance of having a good diet, but the key to the food-as-medicine concept is getting tailored, nutritious meals to those who will see the most benefit.

“We have to make sure that these interventions are getting to the people who need them most,” she said. “We have to match care to need.”

She said research has shown building out programs like this nationwide could avert more than a million hospital stays, generating potentially billions of dollars in savings.

Project Angel Heart touts data spotlighting its impact, examining health costs before and after clients get meal deliveries.

Medically tailored meals contributed to a 13% drop in the rate of hospital readmission; total medical costs for those with certain serious, chronic diseases fell by 24%. That’s according to Project Angel Heart, relying on data from the Colorado All Payer Claims Database.

Project Angel Heart has been living its mission for decades.

In early December, Denver Mayor Mike Johnston was on hand to celebrate a mind-boggling landmark: The group recently served up its 10,000,000th meal. He marked the occasion by wearing a red apron and black hat with the group’s logo.

Johnston called the program’s impact “incredible,” spotlighting its reliance on donations and volunteers.

Between 5,000 and 7,000 people volunteer for the organization each year, totaling about 70,000 volunteer hours annually, Ryan said. The nonprofit has a $7.2 million annual budget.

“Almost all that is a volunteer network,” Johnston said after touring its kitchen, housed in a renovated brick building on Washington Street north of I-70.

“It just shows people’s capacity for generosity is almost limitless, particularly if you give them an important cause and a chance to work together toward delivering it,” he said. “So yeah, it was the city at its best for me.”

“It’s also the personal relationship,” he added, “That comes with knowing that someone loves you enough to make you a hot meal, package you a hot meal and deliver it to your house.”

After packaging that milestone meal, the breakfast bowl with a 10,000,000th meal sticker was soon out the door and handed off by Charles Robbins to its recipient, Diane Roybal.

“We’re just delighted to be able to deliver it to you,” Robbins said.

Back in 1991, Robbins got the ball rolling on what would become Project Angel Heart, putting together a group to hand out the first meals, donated by the restaurant Racines, to HIV and AIDS patients.

“We packaged up the lasagna and a salad and put magazines and roses in the bags, and drew little notes on the bags as well,” he said “And we had a small band of volunteers that delivered them that day. And that’s how it started.”

“It means a lot to me to be able to get it,” Roybal said of the 10,000,000th meal. “It was a nice surprise that I was given the honor, and it’s an honor to get this today and a blessing to get these once a week to have them in my fridge when I need them.”

To read more stories from Colorado Public Radio, visit www.cpr.org.