SALZBURG, AUSTRIA–How does the chairman of the world’s largest food company–Nestlé S.A.–view consumer trends toward organic foods, slow foods, and farmer’s markets in parts of the U.S. And Europe?

“You have to be rational,” says Peter Brabeck-Letmathe, Chairman of the Board of Nestlé S.A. “There’s no way you can support life on earth if you go straight from farm to table.”

Nestle, like many “big food” companies in recent years, has made acquisitions of several premium brands that organic-loving people tend to buy: San Pellegrino water, PowerBar energy bars, and Skinny Cow ice cream. The company has also tweaked its motto in recent years to de-emphasize candy bars and shift the focus to health and wellness: “Good food, good life.”

But when it comes down to it, Brabeck-Letmathe thinks organic products (known as “bio” products in Europe) are not key to Nestlé S.A., which had sales of 110 billion swiss francs and profits of 34 billion in 2010.

“It sounds good. It is good. We have to help our farmers who make these products. It allows them to create added value for people who are willing to pay for it,” Brabeck-Letmathe said during an interview at the Salzburg Festival, where Nestlé S.A. sponsors the Young Conductor’s Award. But “it’s a privilege. We also have to think of the world food supply.”

Brabeck-Letmathe says that “bio” products have 30% less yield than normal agriculture and “wouldn’t allow us to feed the world today.” Certainly, wealthy people in areas rich in agriculture, like Austria, Germany, and the U.S., have the privilege to pay higher prices for organic foods. But he views it as a “romantic” notion that is not scalable.