Many of the food industry’s problems can perhaps be summed up by the humble buttered-popcorn jelly bean. Love or hate this sweet treat, its 1989 introduction was a chewy harbinger of food scientists’ ability to make any food taste like any other food. If a sugary candy could send savory signals to the brain, what else was possible?

A lot, it turns out. Flavor technology has evolved rapidly in recent years. Forget about candy that smacks of toasty popcorn; lab-grown meat is now practically indistinguishable from the real thing. But as much as advances in bioengineering have leveled up the veggie burger beyond belief, among myriad other breakthroughs, they’ve also let loose a deluge of so-called health foods that might not be so healthy in the long run. The new documentary Food, Inc. 2, which is now playing in select theaters and available for rent on streaming platforms, argues that when a product’s calorie or fat count appears too good to be true, your brain and body may suffer from the deception.

Food, Inc., which came out in 2008, used corporate farming as a launchpad for exploring all manner of unethical practices in the modern food industry. Although some in the industry argued that the film offered only a one-sided interpretation, the Oscar-nominated documentary resonated so deeply with audiences, it nearly derailed filmmakers Robert Kenner and Melissa Robledo’s careers. Rather than move on to another project right away, the pair found themselves occupying dais-side seats on a never-ending rotation of food panels.

“There was a total explosion of interest that caught us by surprise, frankly,” says Kenner.

That explosion was accompanied by massive shifts in the culinary landscape. In the years after the film came out, the then-burgeoning Food Movement galvanized interest in environmental, nutritional, and labor concerns; the number of farmers markets spiked; and so did healthy alternatives in grocery stores. Also happening soon after: Wide adoption of the phrase “ultra-processed foods,” even as these foods continued to proliferate on store shelves.

Although Food, Inc. 2, like its predecessor, takes a shotgun-spray approach to covering several troubling topics, it spends a significant chunk of its runtime on ultra-processed foods—and how the additives within them are rewiring consumers’ metabolisms.

Schatzker’s main area of interest lies in the sensory aspects of food, which he unpacks in his books, The Dorito Effect and The End of Craving. Kenner and Robledo met the author while researching their film and ended up relying on him—both behind the scenes and onscreen—to help translate some of Food, Inc. 2’s more dense scientific concepts in a manner that is, well, more digestible. His work came to their attention through Yale professor Dana Small, whose experiment on fake sugar, which appears in the film, offers a crystal-clear distillation of how the brain and the body interact with food.

Small has a history of studying how the brain processes food reward. In 2001, she conducted what she believes is the first neuroimaging study of feeding in humans, monitoring the response to chocolate in areas of the brain that represent pleasure of eating. In the documentary, she claims Pepsi was interested in this research, and approached her many years later about finding a way to decrease calories in a sugar-sweetened beverage, without compromising reward. Small fed her volunteers a series of equally sweet beverages with different caloric content, and observed how their brains expressed food reward.

Her team expected that the most caloric beverage—the one with a 75-calorie taste and 150 delivered calories—would be the consensus favorite. That honor, however, fell to the middle-sweet, middle-calorie beverage—the one with a 75-calorie taste and 75 delivered calories. Through follow-up studies, Small discovered that when sweetness matched calories, the subject’s body metabolized that energy; but when something was too sweet for the amount of actual calories present—or not sweet enough—the mismatch ended up blunting their body’s natural metabolic ability. In the latter case, those calories weren’t being turned into fuel, but instead potentially accruing into fat.

Other scientists have conducted experiments with rodents to show that fat replacers have a similar effect, disrupting signals that could help control the rats’ food intake, and causing them to gain weight as a result. Too few studies in this realm have involved humans, though; something Schatzker attributes to the fat-replacer industry keeping a lower profile than that of artificial sweeteners, which have public-facing brands like Equal and Splenda. He believes more human studies need to happen around other additives, so people understand the full scope of health risks from ultra-processed foods.

Throughout their film, directors Kenner and Robledo weave the thread of ultra-processed foods in a broader tapestry of corporate responsibility. They depict how factory farms are overproducing, driving down the cost of raw materials, while processing those materials into unrecognizable culinary concoctions that drive up profits for the companies selling them. But while the film presents evidence that suggests ultra-processed foods drive consumers to eat them in excess, it also portrays corporations as reluctant to improve those foods’ nutritional value. 

For instance, in the documentary, Small claims that when confronted with evidence that reducing calories with artificial sweeteners might be doing more harm than good, Pepsi questioned the data, claiming it didn’t make sense. Not long after, she alleges, the company pulled its funding. (Pepsi declined to comment on the claims in the documentary.)

“No one ever needs to put a warning label on real food.”