Therefore it is safe to assume that diet containing poly-saturated fats is a much clearer and present danger than environmental factors, which on their own cannot be discarded or disregarded.

Might there be environmental changes that go along with the homogenization of the American diet and the spread of the typical American diet around the world? What might those environmental risks be?

Yes. The whole industry and the various feeder industries associated with the fast food industry are more like to create environmental factors. For example Trans fatty acids and poly-saturated fats are the result of the specific kind of diet that animal breeders use to make their animals fatten up and produce the greatest output. Most trans-fatty acids in the U.S. diet are produced industrially as a result of hydrogenation of vegetable oils. However, smaller amounts are present in meat from cows, sheep, and other ruminants. The predominant trans-isomer...

It is possible to change the trans-fatty acid content of ruminant products to some degree by altering the animals' feed. Over all this means a substantial change in the industrial structure and consumption patterns which have their knock on effect on environment. Over a generation or two these artificially introduced fats become part and parcel of the genetic make-up of the animals used for meat in these areas. Therefore it is plausible to argue that homogenization of American diet both in the United States and across the world will also have a knock on effect on the production of the various raw materials including meat which would now be catered to the tastes and requirements of the American Fast food Industry. All of this is more than apparent in countries like Thailand, China, India and Pakistan where people have taken to American diets like fish takes to water.