Harvey Levenstein, professor emeritus of history at McMaster University, has written two books documenting the eating habits of North Americans.

Food costs are joining gas prices in skyrocketing as farmers switch to producing crops that can be converted into alternative fuels. Corn, sugar cane and soybeans are among crops that can be turned into ethanol, yet these are also staple foods in many parts of the world.

Harvey Levenstein, food historian and professor emeritus of history at McMaster University in Hamilton, Ont., has documented how eating habits in North America have changed since 1880 in two books, Revolution at the Table and Paradox of Plenty. He discussed the changing nature of food supply and demand with CBCNews.ca.

Do we have an impending food crisis?

There is a crisis. Rising food prices are having a very adverse effect on many poor people around the world. I noticed a couple of years ago, before all of this, American subsidies to their corn producers were raising corn prices in Mexico, where corn tortillas are the staple for about 40 per cent of the population. They were being squeezed even before all this biofuel stuff began to have an impact.

Now it's happening throughout the world, particularly in rice-growing countries. I think there's no doubt it is happening.

The thing you have to watch is that the aid organizations and the people who should be trying to raise money and food have an inherent tendency to inflate statistics. Some of them have admitted, with regards to previous famines in Africa and the number of people starving, is routinely exaggerated out of hand. Even given that, it seems clear just from the general numbers that a lot of people are seeing their diets restricted either in terms of the amount they can eat or the quality of their diet.

As a historian, you can say that this goes back to one of the cycles in the histories of people's perceptions of food. It goes back to the early 19^th century to Thomas Malthus and the recurring cycles of the Malthusians, who are always predicting the population is outstripping the world's supply of food, which will lead to disaster.

[Then there are the] cornucopians, who are people that think science and technology are going to come up with ways and always do come up with ways to meet demand.

In the 1970s we were worried about the population outstripping the food supply and American foreign policy was getting ready to turn to exploit this coming crisis, which was associated with the new Ice Age.

Food and gas prices rose in lockstep in the 1970s, at a time when there were fears the world was heading into a new Ice Age. How is this cycle different, and isn't it ironic that global warming is today's concern?

It is ironic. Some people are saying the drought in Australia is one of the causes for the shortage of wheat, and that it's a permanent change that is the result of global warming and it's ultimately going to knock Australia off as one of the world's great wheat exporters.

For the most part, the causes seem to be more short-term and people are saying there are medium-term solutions for improving agriculture.

They're singing the cornucopian song, saying one of the reasons we haven't been looking at improving agricultural productivity and so on is because of the surpluses that farmers have been producing for the past 20-odd years.

Is this going to lead to greater processing of food and more use of technology?

Over the short term there are going to be pushes for more technology on the farms. In the short term that means more fertilizers, but they're uneconomical for poor farmers. When I say more technology on the farm, that's thinking in terms of Third World places, particularly Africa. That can be really difficult to pull off because fertilizer is just too expensive for many of these places.

It also involves a complete shift in their farm economies from producing for export back to producing for their own food needs. It's very difficult but some people are saying that's the way to go.

The International Monetary Fund and the World Bank and such bodies that have been promoting Third World development have been concentrating on manufacturing or processing exports rather than on producing food. Now they have to do that. There are no short-term fixes.

How are eating habits going to change in North America? Are we going to eat more processed food or are people going to go the other way with a more organic diet?

There are two things involved. At the root of the crisis is the rising price of grain. That's going to have little effect on most of the grains we eat because most of them are so processed and packaged that the food itself represents a tiny amount of the cost of the product.

How much do the potatoes in potato chips cost? Or the grains in Cheezies?

The majority of the price of a bag of potato chips goes comes from its packaging and marketing, historian Harvey Levenstein says. (Mark Lennihan/Associated Press)Snack foods, for example, are large parts of many people's diets and will hardly be impacted at all. If you go down the aisle of the supermarket and look at the amount of the price from the food that ultimately goes to the farmer, it's only a very minor part. This even goes for fresh fruit and vegetables, where so much of what we pay goes to the cost of transporting it, the middleman and so on. How much of it ultimately goes to the guy in Peru that grows the asparagus, versus what we pay for it? And that asparagus isn't even packaged.

It's not really going to have that much of an impact on our diets. It probably will lead to rising prices of meat, but there people usually just switch meats. They'll either start buying cheaper cuts or switch from beef to poultry.

Right now, poultry is so cheap that I don't think even if the price doubled it wouldn't make much difference in most people's consumption of it.

I don't think it's going to have much of an impact here frankly.

You said in Paradox of Plenty that food rationing during the Second World War resulted in Americans having the healthiest diet at any point in their history. Can we infer from that that people eat better during times of shortages?

That may have been true but I don't think so anymore because now we've had a complete reversal thanks to things like high fructose corn syrup and so on. Now, the worst foods are the cheapest foods.

This guy I know at the University of Washington has been churning out papers showing how people always condemn poor people for eating all this processed snack food and drinking pop. He's shown that calorie for calorie it's much cheaper to eat what we consider an unhealthy diet based on snack food and pop. Whereas, to eat a healthy diet of fresh fruit and vegetables, with lean meat and a lot of fish, is very expensive.

I think the opposite might happen — our diets might get worse.

How integral has technology been to food processors and fast food companies?

It's an incredible business when you look into it. The extent to which they've used chemistry in particular to make foods that no one dreamt would be possible before the war is really quite impressive.

They spend a hell of a lot on research and development — much of it is to make things easier to eat, to reduce the amount of preparation. That involves processing things more in factories rather than in kitchens.

The history of food is the steady procession of the preparation of food outside the home. This is really the history of food for the last 250 years, if not forever.

'The history of food is the steady procession of the preparation of food outside the home.'

The people spurring this are the food processors and manufacturers who recognize that for the most part this is what people, and women in particular who are still the major food preparers, in our country, want. That is, to prepare less of the food at home and have it more prepared by other people.

In the course of things, they've developed all sorts of things that allow it to be preserved practically endlessly. This goes right back to the farms to developing crops that can stand being transported over thousands of miles without deteriorating, to processing these crops in ways that will again preserve them and precook them so the amount of preparation will be minimal.

This involves real feats of chemistry, starting of course, with the biology of crossbreeding and genetics and all that and ending with having to bash the food around, which is essentially what they do — deconstruct it in these factories and reconstruct it by adding chemicals and processing in certain ways so that it won't deteriorate and so that it will have some taste. A lot of it involves putting taste back into the food that processing deprives it of, so they have all these artificial flavourings and so on — which are of course called "natural flavours."

This is a long-term trend that isn't going to be reversed.