It probably has to do with how some technologies scale. For example, processing power advances exponentially with time (see Moore's law). Few other things do. The things you would consider a "necessity of life" have scaled linearly, if at all.

Food production has certainly advanced with GM crops that are resistant to insects, droughts, etc. and produce more edible material per acre, but not that much more. Fertilizers and insecticides have also improved yields, but just a bit. Farm machinery has advanced tremendously but, as discussed in the article, it lets fewer farmers work more land rather than making the land itself more productive. Food is still pretty expensive to produce. Most nations do produce more food than they can consume though, even some that experience famine. Distribution is still a big problem and a huge part of the cost of food.

The average person now has access to a huge variety of foods from distant places. Transporting food costs a tremendous amount, both in terms of money and environmental impact. This is why you often hear about local foods being better for the environment. However, a rather large portion of the world's population has only seasonal access to locally produced fresh produce, which we now consider necessity for good health. If, like a large portion of the world's population, you live in a place where fresh produce is seasonal, consider what your diet would have looked like before canning came along. Technology has performed wonders for the average person's winter diet!

Of course, technology has a funny way of turning on itself. The triumph of spinach, oranges, and bananas in January has been followed by potato chips and cola. We turned food from a necessity into an addiction. Brilliant minds toil away in corporate labs, trying to find some new way to increase the "mouth share" of their product lines. The goal is not to satiate, but to arouse never-ending hunger for your product!

One simple, practical thing that could be done would be to rework farm subsidies. Corn is one of the most heavily subsidized crops in the U.S.. Corn farmers are paid well to produce a crop that has often not been in demand. One root of the anti-globalization movement is the Zapatista revolt in Mexico, which was, in part, sparked by NAFTA flooding the Mexican market with super-cheap subsidized Iowa corn and putting marginal, non-mechanized unsubsidized corn-farmers out of business en masse. Domestically, it's not a huge surprise that high-fructose corn-syrup found its way into most processed foods. High-fructose corn syrup is cheap because corn is cheap, and corn is cheap because our taxes pay farmers to grow it. If you look at the other top subsidized crops in the U.S., you'll not a common theme. After feed-crops (mostly corn), there's cotton, wheat, rice, soy, dairy, peanuts, sugar, wool tobacco[1]... It's mostly high-calorie crops rather than high-nutrient. How Tobacco snuck in there, I have no idea.

Why not change subsidies to be aware of crop destination and emphasize dietary health? Slap a big-ol subsidy on spinach and broccoli sold fresh to market and obliterate the subsidy on corn used for high-fructose corn-syrup. Healthy foods get cheaper, unhealthy foods get more expensive.

[1]http://en.wikipedia.org/wiki/Agricultural_subsidy#United_Sta...