Nutritionist Rachel Davis, who will be racing the Boston Marathon this year, practices what she preaches when it comes to eating for performance.

We liked nutritionist Rachel Davis right away for those three little words every runner wants to hear: “Eat the pizza.”

“Here’s the thing,” Davis says. “There are no ‘bad’ or ‘off-limits’ foods. It’s just that some require moderation.”

Davis knows firsthand you can’t tell a runner not to eat something—as a lifelong runner herself, she knows just how delicious that post-marathon pizza can be (“Preferably followed by ice cream for dessert,” Davis laughs).

Davis, who took up running as a child to emulate her big sister, eventually became a collegiate track and field athlete specializing in the 400-meter hurdles. It was during that time Davis became fascinated with the connection between food and performance, experimenting with various nutritional strategies to learn how it affected her running times. This scientific mind led to Davis getting her master’s degree, then a doctorate, in nutrition sciences.

All the while, she kept running. While in graduate school, Davis ran her first marathon—and surprised herself with a win and a time of 2:48:42. But the trophy wasn’t the best part. “I fell in love with the distance and the training process,” she says. “The months of preparation and duration of the race teach patience and perseverance, and I love that challenge.”

The marathon also offered Davis an opportunity to put her studies into practice. She was particularly interested in why so many of her fellow runners were following fad diets with extreme restrictions on certain foods—and struggling as a result.

“We are so misinformed on proper nutrition these days, and sadly, current fads are more understood than facts,” she says. “Because these fads are often contradictory to how we should be fueling ourselves as runners, I’ve made it my mission to advocate real nutrition and food as fuel.”

She achieves this through her nutrition coaching business, where she helps runners design fueling plans that work with—not against—their life.

“I believe extreme structure can sometimes negatively affect our relationship with food,” Davis says. “I’m especially passionate about serving as a role model for young girls who are growing up in a world that often encourages restriction over proper nutrition. Speaking at events for Girls on the Run, youth athletes and local running groups has become the favorite part of my job.”

Davis leads by example on her website, where she chronicles her recipes as she trains for the 2019 Boston Marathon. She’s also chasing a 2020 U.S. Olympic Marathon Trials standard of 2:45:00, after which you can bet she’ll be ordering a pizza.