When Junk Food Becomes Fuel

From my most faithful correspondents, an article in the Telegraph about how junk food is being converted to fuel. The
article is at http://www.telegraph.co.uk/finance/news ... -fuel.html

I only wonder about how much energy is expended in converting this stuff into fuel.

Alarming thought that the fat content is high enough to be converted easily into bio diesel.

I have heard of people running vehicles on used chip-shop cooking oil, which is perhaps a more direct route from fat-fryer to internal combustion engine.