Yes, the ABC documentary is very interesting.
Here is an in-depth account of the history of the Western diet that has conquered the world:
Sugar: The Bitter Truth http://youtu.be/dBnniua6-oM
Many of effects of the modern diet may still be unknown.
Scientific research in the life sciences often involves controlled animal studies over several generations. The challenge with the human diet and human triggered environmental influences, such as the large scale release of human engineered chemicals that stay in the environment for decades or longer, is that it is often difficult to impossible to find control groups that are not affected.