SWEAT: Listen up, Valley couch potatoes. Slothful...

SWEAT: Listen up, Valley couch potatoes. Slothful nibblers of chocolate. Imbibers of holiday cheer. ‘Tis time to pay for the dual sins of overdoing food and underdoing exercise. . . . There’s no sitting still at Billy Blanks’ World Training Center in Sherman Oaks. The former karate champ, ballet dancer and actor, above, puts dance, weights and karate kicks into routines. Blanks, a West Hills resident who trains Wayne Gretzsky, says his studio is hot because “it’s something different. Everybody loves the workout.”

DRUG THERAPY: Everyone seems to be talking about “phen-fen.” The name stands for two appetite suppressant drugs, Phentermine and Fenfluramine. At UCLA’s Obesity Center, which combines use of the drugs with diet and exercise, one-third of patients gain weight back in two years. But that’s better than other diets that fail 95% of the time. So says center co-director Morton Maxwell, who runs an identical program in Sherman Oaks.

FAT FINDINGS: Maxwell says recent research puts the lie to our cultural bias that being fat is a character flaw. He notes that the newly identified obesity gene, leptin, is undergoing study. And he predicts that new treatments, such as the use of beta 3 receptor agonists to increase metabolism, will be soon available. But he cautions that obesity treatment is held to an unrealistically high standard by the public, with success defined as attaining and maintaining a low weight forever. No one would expect that much success from, say, blood pressure medicine.

MODERATION: Where diet and exercise are concerned, CSUN professor of nutrition Lillie M. Grossman preaches moderation. She’s appalled at “compulsive” exercisers who pig out, then pound their bodies into oblivion at the gym. “They’re crippling themselves,” says Grossman, a fitness instructor. She cautions against a post-holiday diet unless you’re ready to commit to it. . . . Her take on the obese? “They live their lives or make their food choices differently than I do.”