The New York Times link that you include here did not work. I have based my answer on this article, which seems to be the one for which you are looking.
The basic forces that have changed our eating habits are globalization and modernization. Let us look at each of these in turn.
Modernization led to changes in our diets largely because it created the need for convenience food and the opportunity to get such food. Modernization led to families having busier schedules, sometimes due to both parents working outside the home. As families became busier, they stopped having time to make and eat the sorts of foods that they once enjoyed. At the same time, modernization led to the creation of things like TV dinners and fast food restaurants. These allowed busy people to get inexpensive and convenient food, though that food tended to be less healthy than what we traditionally ate.
Globalization took these changes and spread them across the world. As the New York Times article tells us, it brought the changes to Greece, where people eat more like Americans than like traditional Greeks. Thus, modernization and globalization between them have been changing dietary habits around the world.