But how much “choice” do consumers really have when the food system is overwhelmingly dominated by cheap, processed foods, and when the companies selling them spend billions on marketing and keeping consumers as ignorant as possible about how those foods are produced? And how much “personal responsibility” can people be expected to exercise when they live miles from anywhere that fresh produce is sold?

“Free choice implies informed choice,” said Joan Dye Gussow, who has been writing about the dangers of processed food since the 1970s. A retired professor of nutrition at Columbia, Gussow is 85 years old, but could easily be taken for 60. Consumers are purposefully kept in the dark about where their food comes from and how it is produced, she said.

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She spoke Monday night during one of a series of lectures at the University of California at Berkeley hosted by professor and journalist Michael Pollan and author Raj Patel called “Edible Education 101: The Rise and Future of the Food Movement.” Gussow was a guest along with Michael Moss, a New York Times investigative reporter and author of the bestseller Salt Sugar Fat: How the Food Giants Hooked Us. The weekly series runs through April.

The audience of about 500 was made up overwhelmingly of Berkeley students, many of whom were munching snacks washed down with soda or bottled water as they listened to all the tricks the food industry uses to get them to buy more unhealthy food.

All four participants agreed that the industry can’t simply be reformed to make processed foods sufficiently healthy — wholesale change is needed. Gussow even used the word “revolution” to describe what needs to happen, and called the idea that the food industry can be worked with “ridiculous.”  Moss said flatly that we “can’t tweak the industry.”

They all also agreed that government action is unlikely to do much. The government is “incapable,” in the face of so many marketing and lobbying dollars, Moss said. And efforts like Michelle Obama’s “Let’s Move” campaign in some ways play right into the hands of the industry, which often tries to divert attention away from Americans’ collective, prodigious intake of fat, salt, and sugar by noting how collectively sedentary we are.

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Moss said that it’s nearly impossible to keep his family completely free of processed foods, so he provides incentives for his kids to make the best possible choices among a lot of bad ones. For instance, he has them hunt for the breakfast cereals with the lowest amounts of sugar. That’s not easy, not only because there aren’t all that many low-sugar cereals, but also because shelf placement is carefully engineered to make the least healthy choices the most accessible. But making a game out of it makes his kids feel more in control of their choices, and it’s fun besides. “They like the cereal better because they were involved” in choosing it, he said. And also because “it’s empowering to find out all the tricks [the food companies] are playing.”

And yet, they’re still eating processed foods, as most of us are, because we’re left with little choice. Gussow once believed that educating young people was “part of the answer,” but she no longer does. “It’s overwhelming,” Gussow said. “It’s in your face, all the time.”

And there lies the central conundrum. “Free choice” is a sham, but it’s also the only thing that will create change — people voting with their dollars to, as Gussow put it, “get most of their food not from the supermarket,” but rather from produce merchants, farmers markets, etc.

How difficult will that be? Consider this offhand observation by Gussow: “I have a son who goes to Wal-Mart to buy meat.”