A couple of centuries back, folks ate food that was grown quite close to where they lived. It seemed natural. But as time went by, they started yearning for food that was grown in other places but not theirs. They were able to get these, thanks to the progress in transportation technologies. Today, it has come to such a stage that most of what we consume (and it not just about food) are imported from regions far away from where we live.
To some extent, I guess you can justify consuming products that are not local. For instance, not every food that is healthy could be grown in any specific region alone. In addition, sometimes it makes sense for your region to grow what grows best there are barter these with products from other regions where they grow best.
In many other cases, I opine that locavorism makes tremendous sense, both to your health and pocket and to nature's! And let's not think locavorism is a fad, and I am not advocating locavorism because it brings down the cost of transportation and hence, the carbon footprint from a particular food product. As this post's author advocate locavorism, I also think locavorism is more about building a sustainable and prosperous community around you than just reducing the total energy costs of food items.