The experiment starts before anyone takes a bite. There's no drive-thru. No cashier calling the next order. No glowing sign announcing the restaurant is open.
But there is something instantly familiar: the smell of French fries.
Inside a tucked-away laboratory in East Hall at the University of Michigan, researchers recreated a fast-food restaurant-not to serve lunch, but to answer a question millions of people wrestle with every day: Why do people make different food choices in tempting environments than they intended?
U-M psychology professor Ashley Gearhardt said the answer may have less to do with willpower and more to do with the environments designed to shape behavior.
Years earlier, as a graduate student at Yale studying alcohol addiction, Gearhardt worked inside a simulated bar built to understand how surroundings influence decisions.
The experience sparked an idea that stayed with her: If researchers could recreate a bar to study drinking, could they build a restaurant to study eating? That question became one of the university's most unexpected research spaces.
To make the environment feel authentic, Gearhardt visited restaurants across Ann Arbor and paid attention to details most customers rarely notice-lighting, seating, menu placement, colors and, above all, scent.
One pattern stood out. People often smell fried food before they ever see the menu.
Today, that insight lives inside the lab. Menu boards line the walls. Tables mirror restaurant seating. A working kitchen prepares cheeseburgers, fries, cookies and milkshakes alongside healthier options like salads and grilled chicken. Students wear restaurant uniforms.
The goal is simple: make the experience feel real.
The space is home to the Food and Addiction Science and Treatment (FAST) Lab, where Gearhardt and her team investigate whether highly ultraprocessed foods trigger brain and behavioral responses that resemble addiction-like patterns in some individuals.
Using tools ranging from brain imaging and behavioral studies to this simulated restaurant, researchers explore how everyday cues-from commercials and product placement to smell itself-can intensify cravings and shape decisions.
"We can bring people into this really tempting environment to understand-in a real-world way-how it may trigger behaviors, biology and psychology that keep people stuck in unhealthy patterns of food intake," Gearhardt said.
Ultraprocessed foods are often built from industrially formulated ingredients uncommon in home kitchens-including high-fructose corn syrup, modified starches, emulsifiers and processed fats-and now make up a substantial portion of calories consumed in many diets.
One early finding revealed just how powerful the environment can be. Participants randomly assigned to the restaurant setting reported stronger cravings, worked harder to obtain food rewards and consumed hundreds more calories than participants in a neutral room.
But they didn't enjoy the food more. The environment increased wanting-not liking.
That distinction may help explain why resisting certain foods can feel far more complicated than simply exercising self-control.
"We now know our brains are competing with a multitrillion-dollar industry investing enormous resources into making products as irresistible as possible," Gearhardt said. "And they've done a pretty good job. But we're the ones paying the cost with our health."
For students working in the FAST Lab, the experience extends beyond collecting data. Sharon Santosh, a senior studying mathematics and biopsychology, cognition and neuroscience, joined the lab after developing an interest in how food quality influences health.
Her time in the lab reshaped how she thinks about food-not only personally, but systemically.
"Learning more about the technologies and tactics used in the food industry completely changed the way I think about eating," she said. "I pay more attention to food quality and how food makes me feel physically and mentally."
The experience also helped her develop research skills and something less measurable: learning how to balance scientific rigor with helping participants feel comfortable and supported.
For Ian Kuentz, a senior psychology major, the lab connected directly to his long-standing interest in addiction and reward.
"Food addiction is one of the most exciting areas in reward research because it brings together so many fields-from neuroscience to food science," Kuentz said. "I didn't realize how quickly the science evolves or how much new research is constantly shaping what we know."
Working in the FAST Lab changed his own habits, too.
"You start to notice how much the environment influences your choices," he said. "I've become more intentional about what I eat and how I build my own food environment."
Today, researchers continue exploring whether diets centered on minimally processed foods can reduce cravings over time and improve long-term health.
For Gearhardt, the goal isn't to recreate fast food.
It's to recreate reality-and better understand why resisting temptation may be far more complicated than simply saying no.
