Very few Americans look to lawyers to save them from their Cheeto-munching selves. But that hasn’t stopped the plaintiff’s bar, in search of its next supersized payday, from fixing its sights on your waistline.

At a conference last weekend in Boston, an organization called the Public Health Advocacy Institute (PHAI) set the stage for ambulance chasers who see dollar signs where the rest of us see dinner. Promising a courtroom battle of the bulge, PHAI is attempting a Hollywood-style extreme makeover of the common sense weight-maintenance equation: Calories in (food consumption) must equal calories out (exercise).

By giving “calories in” a major close-up, editing personal responsibility out of the script, and casting a few culprits with real pizazz (read: fast food), PHAI has managed to create a red carpet media circus. This strategy may swell trial lawyers’ wallets, but it ignores the one thing that might actually help Americans keep off the pounds: physical activity.

The real action comes from the “calories-out” side of the equation. “In a debate in which foods themselves are being held to be largely responsible for increasing levels of obesity,” former FDA Commissioner Dr. Mark McClellan observes, “actual levels of caloric intake among the young haven’t appreciably changed over the last twenty years.”

A growing body of academic research corroborates Mr. McClellan’s point. Using Census data, the University of North Carolina’s Dr. Lisa Sutherland has shown that teenagers decreased their physical activity by 13 percent since 1980, while their caloric intake rose just one percent over the same period. According to an article published by the American Medical Association, a lack of vigorous physical activity is the main contributor to obesity in children ages 11 to 15.

The same holds true for adults. “A reduction in energy expenditure must be the main determinant of the current epidemic of obesity,” a 1995 study published in the International Journal of Obesity found. And a 2003 study in the American Journal of Preventative Medicine summed it all up by recommending “a focus on increasing energy expenditure, rather than reducing caloric intake.”

Here’s the most amazing thing. Skinnier people tend to eat just as much as heavier people. “Most studies of food intake show that obese subjects do not eat more than nonobese subjects,” reports a study appearing in the American Journal of Clinical Nutrition. Why the weight difference? Heavier folks tend to exercise less.

Don’t tell that to PHAI. Given its blame-food-first mentality, it’s no surprise that physical activity wasn’t mentioned once on its agenda. Instead, PHAI’s “Second Annual Conference on Legal Approaches to the Obesity Epidemic” discussed such topics as “Are Some Foods Addictive?”

Wouldn’t it be wonderful for trial lawyers if they could somehow cross the bridge from tobacco to food and convince juries that tasty food is addictive? While it’s true that we need food to live, those kinds of considerations rarely stop ambulance chasers who recently learned to chase pizza deliverymen instead. “When lawyers see how lucrative these are,” self-proclaimed movement leader John Banzhaf asserted at the weekend conference, “they will all join in.”

Just one week after PHAI’s first conference “intended to encourage and support litigation against the food industry,” a Gallup Poll revealed that only nine percent of Americans support such legal stunts. No wonder the House of Representatives and a dozen states have passed bills to prevent such frivolous litigation.

So, why do “obesity” trial lawyers focus exclusively on food? Well, gym teachers can’t pay out billion-dollar settlements, no matter how many kids lolly-gag through P.E. class. Mr. Banzhaf says it best: “I can’t sue to make people exercise more, but I can do something about food.”

But perhaps he shouldn’t be so pessimistic. After the Department of Health and Human Services announced that obesity may be a “disease,” Mr. Banzhaf insisted it would be easier than ever to find “victims.” So there may be a whole menagerie of industries out there — just waiting to be sued — which keep people sedentary: House cleaning services, lawn companies, elevators, moving sidewalks, luggage with wheels, electrical kitchen appliances that alleviate the need to mix and chop, and of course, the second family car.

Who knows? Maybe next year we could see PHAI’s First Annual Conference on Legal Approaches to the Sedentary Lifestyle Epidemic, with speakers discussing such topics as “The Addictive Properties of Power Mowers.”