Random Analogies
"A moral barometer is like a diploma or letter of reference. When you apply for a job, credit line, condo, etc, the manager (or whomever) is going to want to see your credentials and references. What's more, s/he might insist that the diploma/reference had been issued by someone/entity of high repute and veracity. So, when an atheist says "I have a moral compass" Our next question becomes: "And from whom were these moral standards established?"
"A trans fat is like a feckless person with narcissism. These are those people who look good and spend time on looking good, have a sense of self-importance and entitlement, are charming and often lead a puffed double life."
A nice article about food labeling.
"With its 250 million nerve fibres the corpus callosum is like an Autobahn for neural data connecting the two hemispheres."

