How much does a can of tuna weigh in grams

Paul E. Brefka, who eats tuna fish at least once a week for lunch, says he recently noticed that the cans seemed to contain more water and less tuna.

An inventor and product designer who is curious by nature, Brefka got out his scale and decided to check how much fish was actually in a 6-ounce can. What he found surprised him.

He tested two cans of Geisha tuna fish and found slightly less than 4 ounces of tuna in each can. He wrote Geisha's corporate parent two complaint letters but never received a response.

When he called us, we decided to put six major brands of solid white tuna on Brefka's scale. The results were troubling. Every can was the same size, but the tuna fish-to-water ratio in each can varied considerably from brand to brand.

Geisha, for example, had the most water and least fish, 3.8 ounces. Chicken of the Sea had the most tuna fish _ 5.1 ounces _ and least water. Bumblebee, StarKist, 3 Diamonds and Stop and Shop's private label brand ranged between 4.1 and 4.5 ounces of tuna fish.

"Everyone I've talked to is amazed at this," said Brefka. "They all look at that label that says "net weight 6 ounces' and expect they're getting 6 ounces of tuna."

Actually, the net weight amount currently includes water. The only real help the consumer gets in determining how much tuna fish is actually in a tuna fish can comes with the serving size information. The standard serving size for tuna fish is 2 ounces drained of all liquid. The manufacturers say their 6-ounce can has about 2.5 servings, or 5 drained ounces of tuna.

Yet, according to Brefka's scale, all of the manufacturers except Chicken of the Sea had less than 5 ounces of tuna in their cans. The shortages ranged from a high of 1.2 ounces with Geisha to a low of a half ounce with StarKist.

It's not much in each instance, but it adds up quickly. Americans buy about 2.2-billion 6-ounce cans of tuna fish each year, according to the U.S. Tuna Foundation.

Brefka also weighed a couple of 12-ounce cans of solid white tuna fish for us and found at least 9 ounces in each of them. That was still less than should have been in the cans, according to the serving-size information, but it was a better deal than the 6-ounce cans.

For example, two 6-ounce cans of 3 Diamonds in our test cost a total of $2.18 and yielded 8.8 ounces of tuna fish. A single 12-ounce can of 3 Diamonds cost $2.09 and yielded 9.2 ounces.

Tuna fish canning companies questioned the accuracy of Brefka's weighing methods. Indeed, he did not follow Food and Drug Administration guidelines for weighing tuna fish. The guidelines run three pages, are as impenetrable as IRS instructions and require special equipment for removing the water.

However, from what we saw, Brefka was far more meticulous than a typical consumer would be. He was careful in draining the water, and his scale was precise.

Debbie Bolding, general manager of communications at StarKist Foods, the No. 1 tuna fish seller in the United States, said her company believes that its cans are in full compliance with the law, but she said StarKist would gladly replace any can that has less than 5 ounces in it.

David Burney, executive director of the U.S. Tuna Foundation, said the industry has been trying for three years to persuade the FDA to approve labels that more accurately describe the contents of a can. He said the "net weight 6 ounces" reference on the current labels causes all sorts of problems.

"It's very confusing for us, for the FDA, and for the consumer," Burney said.

Indeed, an FDA spokeswoman initially told us that a can of tuna fish with the words "net weight 6 ounces" on the label should contain 6 ounces of tuna fish. She later backed away from that statement, saying a law enacted in the early 1970s allowed tuna fish companies to include water in the net weight.

A second law enacted in 1990 set forth standard serving sizes for every product and required manufacturers to disclose how many of those serving sizes were in each container.

The FDA, at the urging of the tuna industry, has now proposed new regulations that would require the net weight information to be based on drained weight and to match the serving size amount. In other words, tuna fish cans in the future will probably say "net weight 5 ounces." Let's hope that's how much tuna fish is actually in there.