The Food and Drug Administration should establish a standardized front-of-package labeling system and provide definitions for contentious terms like “natural,” two federal lawmakers have declared.

Sen. Richard Blumenthal and Rep. Rosa DeLauro (both D-Conn.) sent a letter to FDA Commissioner Margaret Hamburg in response to the agency’s request for comment on the first updates to the Nutrition Facts label in 20 years.

The FDA released proposed changes earlier this year that modernized the serving sizes to reflect the amounts people currently eat and emphasized certain elements like calorie content and servings per container.

But the legislators asked for more.

“While we are pleased that the Nutrition Facts label has been redesigned and updated to reflect the latest nutrition science, we are disappointed that the FDA has remained silent on many critical features that could help consumers make healthier choices to combat the dangerous obesity and diabetes epidemics our country faces,” the legislators wrote.

Sen. Blumenthal and Rep. DeLauro proposed some additional tweaks: defining a daily value for added sugars “so that consumers can understand added sugars in context,” revamping the ingredients list to make it more readable (like grouping sugars together), and adding a requirement for the total amount of caffeine be disclosed.

Conventional foods with added caffeine are on the rise and given “well-documented health concerns regarding excessive caffeine consumption by children and pregnant women, we recommend that FDA require that the amount of caffeine in products be disclosed,” the letter stated.

The FDA should also take advantage of the changes to the labeling system and institute a front-of-package (FOP) labeling system, as recommended by the Institute of Medicine, the lawmakers advised. Food manufacturers “use a plethora of marketing techniques on the FOP to attract consumers and convince them to buy a particular food product.” The establishment of a single, standard FOP labeling system to appear on all products “is necessary to protect consumers from the dizzying array of FOP labels, and the current industry-led voluntary FOP standardization effort that can easily be used to conceal the poor nutritional quality of many products.”

New definitions would also be beneficial to consumers, Sen. Blumenthal and Rep. DeLauro said. “Food packaging today also contains too many unregulated claims that serve to only further confuse consumers.” Terms such as “whole wheat,” “natural,” and “healthy” should all be defined by the FDA. For example, products that contain artificial or synthetic ingredients should not be allowed use the claim “natural.”

“We have high hopes that with these additional recommendations, the new Nutrition Facts label will help steer consumers towards a healthier diet, and will do much to increase the health and well-being of the American public,” they concluded.

To read the letter, click here.

Why it matters: Some of the alterations suggested by the lawmakers would pose significant burdens to food manufacturers. The switch to a FOP labeling system would require major changes in how products are packaged and labeled. As for the new definitions, given the FDA’s reluctance to wade into the quagmire of “natural” claims, it seems unlikely the agency will change its mind now.