PERHAPS YOU THINK that pizzas don't need a great deal of regulation. Perhaps you think that what they generally need is more pepperoni. But the situation, viewed from the proper perspective, is a great deal more complicated than that. It has turned into the kind of illuminating little vignette that tells you a lot about life in Washington, at a certain level.

Political issues often get more bitter and obsessive as they get smaller and more trivial. That is true of the frozen meat pizza case. This micro-grievance seems to have become something of a fixation to the dairymen.

When a pizza is labeled a cheese pizza, the government says that it must contain real cheese. But when it is labeled a meat pizza, the government doesn't care whether it contains cheese or not. The dairy lobby wants it to care. In meat pizzas, the manufacturers mostly use an artificial cheese made of imported casein and soy beans. It tastes the same. It's better for the customer because the cholesterol level is lower. And it's much cheaper because of the grossly and inordinately over-supported prices of milk and cheese.

All the ingredients are reported on the label of the pizza, as on any food product. But the dairy lobby wants a more prominent notice, in the manner of the cancer warning on cigarettes, declaring that the apparent cheese in the meat pizza is not the real article. The lobbyists cherish the hope that the sheer embarrassment would force the makers of frozen meat pizzas to switch to real cheese, opening vast new markets for dairy products.

The dairymen tried several years ago to get the Agriculture Department to change its regulations but got hooted down. Now they have turned to Congress, which seems more sympathetic. They hope to get a pizza-labeling requirement tucked into the budget reconciliation legislation. In a huge bill like that, it wouldn't be conspicuous. But the dairymen would greatly appreciate it. For the customer, of course, a switch to real cheese would mean higher price