When McDonald's Corp. announced last week that it would switch cooking oils to reduce the amount of unhealthy fat in its french fries, I decided to call John Banzhaf. I hadn't spoken to him in several years, but I well remember our first interview, in the early 1990s.

Banzhaf was, and still is, an entrepreneur of litigation, a trial lawyer's trial lawyer, and a capitalist's worst nightmare.

From his office at George Washington University, where he teaches a course called ``Legal Activism,'' he helped orchestrate the campaign of lawsuits that eventually gutted the U.S. tobacco industry.

Way back in the early 1990s, Americans could still smoke pretty much wherever they wished, and the industry was still aggressively resisting, for example, government regulation of smoking in privately owned businesses. Banzhaf told me then that the industry's defensive efforts were doomed.

``Consider fast-food restaurants,'' he said, with a gleam in his eye.

                        Big Mac Asthma Attack

``They go to great lengths to lure kids into their stores. You see all these kids in the smoking section. Now what would happen if one of them had an asthmatic attack? A lawsuit could be brought on behalf of the child, and the restaurant and its owner would be liable for very serious damages.''

At the time, Banzhaf had already served notice to the fast-food chains that he was poised to bring such a suit. Whether the suit ever materialized, he said then, didn't make any difference. The threat would be enough.

``Within two years,'' he predicted, ``you won't be able to smoke in any fast-food restaurant.'' I told him he was crazy. ``No,'' he said, ``I'm right.'' And he was.

Having gained most of their objectives in the tobacco wars, Banzhaf and his fellow litigator-reformers have now turned their attention to food -- fatty fast food, in particular. And once again, their target industry is pursuing a strategy of incremental, pre-emptive surrender.

``I don't think there's any question,'' Banzhaf told me when I called him last week, ``that McDonald's move is in response to the pressure they're feeling from litigation.''

                         No Salad for Caesar

Several lawsuits have already arisen involving fast food and fat. The most celebrated case was filed in July on behalf of a New York man named Caesar Barber, who accused four fast-food chains of luring him into a life of obesity and all the ailments that fat flesh is heir to. Barber's lawsuit became Jay Leno fodder, however, and it collapsed in an eruption of national ridicule.

For the litigators, it was a setback easily overcome. The Barber case, Banzhaf told me, was superseded Aug. 22 by a new suit.

``Barber was an adult,'' Banzhaf says, ``and people could say, `Well, he should be held responsible for the consequences of his own actions.'''

The new suit circumvents any such antique notions of personal responsibility. It does so by employing the most powerful technique of modern reformers and litigators: exploit ``the children.''

Plaintiffs in the new action are two underage girls from the Bronx whose obesity has led to poor health. They and their parents blame McDonald's, which -- in the bloodless terms of the complaint -- ``enticed the Plaintiffs to consume their food products through the use of promotional incentives and marketing directly to children, without properly and adequately disclosing the health effects thereof.''
``The argument is much the same as the one we used against tobacco,'' Banzhaf says.

                         Sounding Scientific

The groundwork for a tobacco-like campaign against fast food has already been set. As with tobacco, the litigators have in hand a helpful report from the U.S. Surgeon General, issued last December, that recasts the problem of bad eating habits in terms of public health. It even imports the term ``epidemic'' from the science of epidemiology and misapplies it to what is more realistically understood as a widespread personal weakness.

Best of all, from the litigators' point of view, the Surgeon General calculated vaguely defined ``economic costs'' of obesity. (The figure is $117 billion a year.) This further removes the notion of personal responsibility from the debate --since I, through higher insurance premiums, must share in the costs of your decision to eat badly.

                            Social Costs

``Some argue that there is a right to voluntarily engage in unhealthy behaviors,'' Banzhaf has written, ``but there is certainly no right to require others to subsidize the huge costs.''

Now, this concept of social costs, carried to its logical end, would shrink the realm of private decision-making into non-existence. Almost any personal decision can be shown to have wider social and economic effects. But the litigators don't want to trace their arguments to the logical end, at least for now.  What do they want, then?

Under pressure of litigation, and eventually from legislators, Banzhaf says, fast-food companies could voluntarily charge ``substantially'' more for their high-fat meals. Food might come packaged with warnings similar to those found on cigarette packages. The fast-food companies might be expected to drop their opposition to a so-called fat tax. They would agree to provide ``healthful'' alternative meals, as defined by plaintiffs lawyers, or face the litigators' wrath.
Banzhaf still thinks big, and sophisticated observers will scoff at the possibility that the tobacco strategy will work on fast food. I suppose you could call him crazy. But I won't. I tried that before.