Over the last three decades, child and adolescent obesity has tripled, with current estimates putting more than one-third of kids overweight or obese and at higher risk for a variety of diseases and ailments, from type 2 diabetes and cardiovascular disease to sleep apnea and joint problems.

A lot has been written about the causes, as in plural, from genetics to lack of exercise. Three new studies, recently published in the journal Pediatrics, place the primary blame on one, big thing: the environment.

"We are raising our children in a world that is vastly different than it was 40 or 50 years ago," Yoni Freedhoff, an assistant professor of medicine at the University of Ottawa told Scientific American. "Childhood obesity is a disease of the environment. It's a natural consequence of normal kids with normal genes being raised in unhealthy, abnormal environments."

Freedhoff and colleagues say a lot of little things add up to a big health issue: oversized meals and drinks, the ubiquity of fast food, the easy abundance of sugary and processed foods, school schedules that prevent teens from getting sufficient sleep, television and a societal imperative to consume.

The good news, researchers say, is that parents can make a difference by specifically addressing every relevant factor. Like pounds, many small improvements can add up. The bad news is that parents can't do it alone. Real, sustained reductions in the childhood obesity rate require broad social change and that, like real, sustained weight loss, happens very slowly.

BODY OF KNOWLEDGE

The hyoid bone, located in the throat, is the only jointless bone in the body. It is anchored by muscles and aids in tongue movement and swallowing.

GET ME THAT. STAT!

Between one-quarter and one-third of all new drugs originate in a university lab, according to Robert Kneller in Nature Reviews (November 2010).

LIFE IN BIG MACS

One hour of typing burns 102 calories (based on a 150-pound person) or the equivalent of 0.1 Big Macs.

DOC TALK

Hyperlipidemia — high levels of fat in the blood, i.e. high cholesterol

PHOBIA OF THE WEEK

Ligyrophobia — fear of loud noises

NEVER SAY DIET

The Major League Eating speed-eating record for a 7-Eleven Slurpee is 22 ounces in 9 seconds, held by Patrick Bertoletti. Warning: Most of these records are held by professional eaters; the rest by people who really should find something better to do. Bertoletti's probably still trying to thaw out his brain.

BEST MEDICINE

Q: What's the most commonly misspelled blood group?

A: Typo.

OBSERVATION

"Whenever I feel blue, I start breathing again." —Unknown

EPITAPHS

On a tombstone in a Vermont cemetery:

Sacred to the memory of

my husband John Barnes

who died January 3, 1803

His comely young widow, aged 23, has

many qualifications of a good wife, and

yearns to be comforted.

To find out more about Scott LaFee and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.