Behind Santa's big belly

Question: If Santa consumed even one-millionth of the goodies kids set out for him at many homes throughout the world, his large girth would be easily accounted for. How might dietary scientists weigh in on this?

Answer: Thousands of years ago, being able to store large quantities of energy-dense fuel in the form of adipose (fatty) tissue spelled survival when food was scarce, says Roger Highfield in "The Physics of Christmas: From the Aerodynamics of Reindeer to the Thermodynamics of Turkey." But today's plentiful food and sedentary lifestyles have nixed all that, bringing on an obesity health crisis. (Note Santa's hardworking trimmer-slimmer elf-mates.)

Scientists are still puzzled, though: Why does Santa crave so much food? Are the satiety mechanisms at work within his brain awry? How are his food energies used and the excess stored? Synchronizing eating habits with energy demands is tricky. Likely, though, it's a head and hormone thing, not a belly thing, even if that is where the world manifestly spots it. Santa, like the rest of us, has inherited a Stone Age brain and its appetites, says Highfield, easier to overeat fats such as ice cream than carbohydrates such as potatoes, and much easier to overdo carbs than proteins (which are almost never put out on those nice-little-kid-offering plates).

Question: What's Santa carrying around anyway — a really really big abdomen, a really really big stomach, a really really big tummy, a really really big gut, or a really really big belly?

Answer: Not long ago, the genteel word "limb" was customarily substituted for the vulgar-sounding "leg," says Mark Davidson in "Right, Wrong, and Risky: A Dictionary of Today's American English Usage." Maybe Santa sported a baby-talk, euphemistic "tummy" in those days, but many people today continue the old practice of using the technical "abdomen" for the supposedly indelicate "belly." But "belly" — old English for "bag, purse" — is the appropriate nontechnical term for the portion of the body between the chest and the thighs. "Stomach" and "gut" won't work because they're actually two organs inside the belly. So belly's best here. Besides, what else within the bounds of rhyme and reason might shake "when he laughed like a bowlful of jelly"? ("'Twas the Night Before Christmas")

Question: How does Santa manage to keep an eye on kids to determine if they've "been good or bad"?