CHICAGO — Tony Pavel, a partner with K&L Gates L.P., was bound to speak about a more active Food and Drug Administration in his Thursday morning presentation at Wellness 10 in Chicago presented by the Institute of Food Technologists.

“You’ve got a lawyer in the morning, and a lawyer with bad news,” he told the audience. “Sorry.”

Mr. Pavel said the warning letters recently sent to 17 companies about claims on the front of packages show how the F.D.A. is taking a harder line with claims. He said he found a ray of hope in a warning letter sent to Nestle U.S.A. about the company’s Juicy Juice Brain Development fruit juice beverage. The F.D.A. warned that a nutrient content claim cannot be made for a food intended for use by infants and children less than 2 years of age.

Mr. Pavel said the F.D.A. said nothing about the company using Brain Development in the product’s name, which he considered a structure/function claim. The F.D.A. thus did not go after a structure/function claim.

“Companies may have a little bit of breathing room,” he said.

Mr. Pavel said industry may expect continued F.D.A. enforcement since Margaret A. Hamburg, the new F.D.A. commissioner, has a public health background, as does Joshua M. Sharfstein, the new F.D.A. principal deputy commission.

“There is a new sheriff in town,” Mr. Pavel said.

He said Dr. Hamburg had a point when she recently said she wants to change the decline in F.D.A. enforcement over the past few years.

“That is changing,” Mr. Pavel said. “That has changed.”

He said he disagrees with Dr. Hamburg’s belief that the F.D.A. has faced unreasonable delays in enforcement. Mr. Pavel said due process should take place and industry should be given an appropriate time to respond.

The F.D.A. has a lot of leeway in accusing companies of misbranding, Mr. Pavel said. The warning letters sent to 17 companies dealt with claims on the front of packages. They covered such issues as nutrient content claims on food for infants, trans-fat claims for products actually high in saturated fats, food products claiming to treat or mitigate diseases, and juice products with multiple ingredients being labeled as single juice products.

“Balance is a key issue that the agency is going after,” Mr. Pavel said.

He added the food and beverage industry needs to stand up for the current GRAS (Generally Recognized As Safe) system.

“I really don’t think there is a need to mess with it,” Mr. Pavel said. “It’s a very powerful tool, and it’s a safe tool.”