In New York City, there seems to be a new scam lurking around every corner. From the counterfeit Rolexes and faux Louis Vuitton handbags peddled on Canal Street, to the fake gemstones and phony diamond earrings hawked on 47th, there is often the overwhelming feeling of the wool being pulled firmly over one’s eyes.

But in a city that takes such extreme pride in its food—boasting tens of thousands of restaurants, markets, and bodegas across some 300-square-miles—the grocery store has historically been sacrosanct to New Yorkers, the lifeblood of the five boroughs.

Still, standing outside of a two-story supermarket near Times Square with Larry Olmsted—the author of the New York Times bestselling book Real Food Fake Food: Why You Don’t Know What You’re Eating and What You Can Do About It—the building feels less like a grocery store and more like a used car lot, housing aisle after aisle of dented fenders made to look like shiny, new Cadillacs.

The concept of “fake food” has existed for centuries, although in recent years, scandals of festering meat in China and wood shavings hidden in parmesan cheese have grabbed major headlines. Olmsted’s book, however, sheds new light on the often subtle and insidious ways food manufactures mislead the public in search of profits. ���The more I found out, the more upset I got,” Olmsted tells me. Donning a checkered button down and a pair of dark, horn-rimmed glasses, he rummages the market’s shelves almost giddily, turning over labels like a detective searching for clues. “I wrote this article for Forbes [in 2012] about “the Great Kobe Beef Lie.” If you go into a fancy steakhouse, and pay $200 and think you’re getting Japanese steak, you are not. There’s not any available in the United States at all.”

Though today nine restaurants in the U.S. now serve real Kobe beef, hundreds more claim to serve the rare Japanese meat on their menus. The response to Olmsted’s article was visceral, with thousands of angry restaurant-goers reacting to the piece online, and the writer began to dig deeper into the dark world of food fraud.

“If people are so pissed off about this issue, what if the staples were faked, too?” Olmsted thought. “I just started researching and found out how prevalent food fraud is. Food fraud is two levels: one is adulteration, and then one is sort of faking the consumer out, like with the Kobe beef story. And it’s prevalent. It’s across every kind of food.

During our hour-long scavenger hunt through a local New York supermarket, Olmsted pointed out the myriad ways in which food companies skirt laws, dupe consumers, and line their pockets. From misleading labels to hidden ingredients, these are the biggest traps to watch out for while shopping at the grocery store.