Dr. Margaret Hamburg, the commissioner of the Food and Drug Administration, has said one of her priorities is to improve the information on food package labels. Her new crackdown on dishonest nutritional claims by food manufacturers is a welcome sign that she means business.

Earlier this month, the agency made public 17 letters it had sent to food companies, accusing them of inflating nutritional claims or masking undesirable ingredients. Several products, including Gorton’s Fish Fillets and Dreyer’s bite-size Dibs ice cream snacks, were cited for labels boasting that they contained no trans fat, even though they had high levels of saturated fat. POM pomegranate juice was cited for misleading claims on the company’s Web site, which is listed on juice bottles, that said the juice could prevent or cure disease like hypertension, diabetes and cancer.

This was not the first time Dr. Hamburg took on misleading claims. Last fall, she helped persuade the food industry to drop its Smart Choices program, which put a “better for you” symbol on products of dubious nutritional value, like Kellogg’s Froot Loops.

The effort to rein in unauthorized health and nutrient claims is a refreshing departure from the laissez-faire approach under former President George W. Bush. It is part of a larger initiative that also has the F.D.A. exploring revisions of the Nutrition Facts panel on the backs and sides of packages  to emphasize calorie content in realistic portion sizes, for example, as the nation confronts a serious obesity problem.