What’s so bad about convenience food?, I asked Michael Pollan – his new book, “In Defense of Food: An Eater’s Manifesto,” has been the number one best-seller nationally for the last few weeks.

“I need to eat in a hurry,” I told him, “so I can rush back to checking my email. What I really need is food I can eat WHILE I’m checking my email.”

“Why don’t you just hook yourself up to an IV?” he replied. “You’re missing something. Eating should be a source of pleasure.” He said the stuff I had for lunch at my computer was not food, but rather something he called “edible food-like substances.”

He seemed to be talking about the breakfast bar I had recently consumed.

“It’s very hard to make money selling you oatmeal,” he said. “Go to the store, you can buy a pound of plain oats for 79 cents. That’s a lot of oats. The companies make money by making breakfast cereal out of the oats. Then they can charge you four or five bucks for a few pennies worth of oats.”

I realized he was talking about Cheerios. Breakfast cereal is inconvenient, I told him, because you have to sit down at a table, and pour milk into a bowl with the Cheerios, and then eat with a spoon.

“For people like you,” he said, “they invented breakfast bars.” I realized he was talking about my Honey Nut Cheerios Milk ‘n Cereal bars. “They have a layer of artificial milk going through the middle,” he explained, “so you can eat your bowl of cereal at the computer, or in the car – no bowl, no pouring milk, no spoon. Then they’re making ten or twenty dollars a pound for those oats.”

So it’s expensive, I said. I can afford a breakfast bar.

“The problem is that every step of additional processing makes the food less nutritious,” he replied. “So they add lots of nutrients back in to the processing so they can make health claims. But they only add what they know is missing. There are other things in whole grains that the scientists don’t know about. You’ll be missing out on that. But you’ll be up to date on your email.”

Then he said the “edible food-like substances” I ate for lunch at my desk were the products of something he called “the nutritional-industrial complex.”

That didn’t sound good.

He explained: “That’s the cozy relationship between nutritional science as it’s practiced in this country, and the processed food industry. The nutritional scientists are telling us every six months what the new good and new evil nutrients are. For the most part, these are well-intentioned efforts to understand the links between food and health. Then you have the food industry, which loves every change in the nutritional weather, because they can then reformulate the food. The net effect is that it makes all the processed foods in the middle of your supermarket look far more healthy and sophisticated than the genuinely healthy food in the produce section, which of course bear no health claims and sit there are silently as a stroke victim.”

That remark about stroke victims made me remember I needed to buy some Pom Wonderful Pomegranate Juice so I could “live young.”

Pomegranate juice, he said, “is a great example of a food where the growers went out and hired some scientists to do some studies, and they found out, lo and behold, pomegranates have some life-enhancing anti-oxidants. They’ve even found that it helps with erectile dysfunction. And the pomegranate, which formerly was a food that was much more trouble to eat than it was worth, has suddenly emerged as one of the most popular fruits in the produce section.

“It’s true that pomegranates are healthy,” he said. “They are full of anti-oxidants – like all fruits and vegetables. There isn’t a plant that doesn’t have good anti-oxidants. But the pomegranate people had the money to go out and get the science to prove it. The broccoli growers, the carrot growers, they don’t have the money for that kind of science.”

I asked Pollan what advice he had for eaters like me. “Eat food,” he said. “Not too much. Mostly from plants.”

Pollan’s previous books include “The Omnivore’s Dilemma: A Natural History of Four Meals,” named one of the ten best books of 2006 by the New York Times. He’s a contributing writer to the New York Times Magazine and is a Knight Professor of Journalism at UC Berkeley.