Jonathan, don’t worry, you really do have a choice whether or not to eat a Big Mac. If you’re in any doubt, try this word game : ask someone who tells you that burgers are as addictive as heroin (a claim that some appear to be making) if he really thinks that heroin is no more addictive than a burger. The Wisconsin study appears to be a touch more subtle, but only a touch. Claiming that certain combinations of fat, sugar or salt can release “chemicals that are similar to drugs like heroin and morphine” in the brain may sound scary, but what does it actually mean? Not much. The fact that we may have “an emotional response to” this food is just a fancy way of saying that we enjoy it – a lot. The notion that this makes such food “addictive” reveals nothing more than the fact that our notions of addiction are hopelessly – and unscientifically – vague. There is another, better, word and it is nicely demonstrated by another expert cited in that article – one Jim Smith of Indiana. Smith claims to wonder whether burgers are addictive, noting that he couldn’t stop at one. “I have to to have two. Same with French fries”.

The word Jim should be looking for is not addiction, but gluttony.