THE WORLD appears intent on finding new uses for body fat.
Not satisfied with using it to provide a thick layer of insulation or an excuse to buy new clothes, people are looking to get more productivity out of their fat. In the competitive pressure of a global economy, fat needs to earn its keep. It can't just sit around watching the soaps like it used to.
First comes news the British arm of McDonald's plans to convert its fleet of 155 trucks to run on biofuel make from its used cooking oil. Once the oil is done frying the fries, it will be mixed with canola oil and added to diesel gasoline.
The second glimmer of innovation comes from the world of plastic surgery, where they can now take fat from your thighs and deposit it in your breasts.
Sometimes the goal is to rearrange the body's proportions, while other times it is out of necessity, as when fat is used to fill in bits lost to surgery.
You can almost hear the thought process at work: Why should I pay for a silicone implant when I have this perfectly serviceable fat right here? (This must appeal to the same sort of people who reuse a sheet of tin foil until it resembles a crinkly doily. Talk about not being able to throw anything out.)
The French fry-powered trucks operate on much the same logic -- waste not, want not. After all, calories are a measurement of energy: the quantity of thermal energy required to raise one gram of water one degree Celsius. Why throw out energy? McDonald's is taking energy from one source to use it elsewhere.
The residue oil is one thing, but what about the oil that is absorbed in the fries? Here the chain of energy use could become vaguely unsettling:
Step 1: Cook fries in oil.
Step 2: Sell fries to customer
Step 3: Customer eats fries, puts on weight.
Step 4: Customer becomes too fat to exercise.
Step 5: Convert remaining fry oil to biofuel.
Step 6: Overweight customer uses biofuel to drive everywhere.
If your teacher were describing this circuitous process in eighth-grade science, she'd use the whole blackboard explaining this sequence of events.
Wouldn't it be simpler to skip several steps?
Step 1: Eat smallish amount of fries.
Step 2: Use energy from fries to walk everywhere.
No biofuel required -- except the biofuel we put in our mouths.
Even better would be a one-step operation that skipped the potato's contribution entirely. Yes, hold the fries -- what we need is a car that can run on thigh fat. The Cellulite 2000? The Thighmobile? The Fatvertible!
There is existing technology to accomplish this right now, but we doubt it will be to everyone's liking. It works like this:
Stand behind car.
Engage quadriceps and hamstring muscles.