I’m reading three books at once right now: Unhinged by Sarah Graves, which is just a pleasant mystery for reading on the porch after the doings of the day, the newest edition of Guerilla Marketing for work, and What to Eat by Marion Nestle.

What to Eat is an enormous tome. I don’t think she’s going to say anything new about what a person ought to eat, but if you are interested in economics, agribusiness, and so on, you will find this book fascinating. She begins with the one thing all nutritionists agree on, all the time: fresh produce. Eat it. But she talks about the economics of it, the cold chain, the reason marketing produce isn’t worthwhile, why we should choose organic and locally grown produce, why we think fresh produce is expensive (it you think so, reexamine that belief — the average cost of those five essential servings per day is 64 cents), why we in Hamburger-a-go-go-land don’t eat fresh vegetables, and the truly startling information that one third of all the vegetables eaten in the United States are french fries, potato chips, and iceberg lettuce.

I had just heard that farmers at the beginning of the 20th century produced 2000 calories worth of food for every gram of oil used, whereas now that number has switched — it now takes over 2000 grams of oil for factory farmers to produce one food calorie. The Omnivore’s Dilemma put it more succinctly: we might as well just sit down to bowls of petroleum.

But the thing that particularly caught my attention was the explanation of how grocery stores work. Guerilla Marketing works with my own concept of marketing: be very good at what you do, and share that information with your customers.

This is not how grocery stores work. They have byzantine systems that ensure that what you pay them has very little connection with what you receive from them. And they make so little money from the foods that you should eat for health that they are really in the business of selling you unhealthful foods. Oh, and nonfood stuff, though Nestle is not discussing that. Nestle says that the problem of poor nutrition in this country is about the fact that there are no economic benefits to good nutrition. Not even to the insurance companies.

Our marketplaces are as complex as our medical system. Reading about either one makes me feel that it is too complex to do anything at all about.

My vegetable garden, the farmer’s market, the local bakery, the meat market — these things keep me out of the system to a large extent, and that seems good.

However, last night I found myself in a discussion of isolationism and World War II. The people talking were all old enough to remember it, so I kept quiet and listened.

They were talking about Roosevelt’s attempts to get the United States to join in the war, and how hard it had been. They were saying that the American attitude of isolationism had been dangerous, and it was fortunate that we had entered the war before it reached “our shores.” We never use the expression “our shores” except in the context of war.

I was surprised by this. One man said, “Even when Britain was brought to her knees, people resisted. Where did they think Hitler would go next?”

So when I read about our current system of agribusiness and my mind boggles, I may be entirely wrong to think that I can just opt out of it and that will help in some way. It seems impossible to sustain our economic system as it operates. When I read these things, it seems like spinning plates — inevitably it will crash. My idea of relying as little as possible on the system may be untenable, just as American isolationism might have been untenable, for all I know.

I suppose this is why it is good to have a novel to read at the same time, in case of excessive mindboggling.