Question: 1 can a day tuna?
Answer: A can of tuna is about 5 oz; drained weight is about 4 oz. If you ate a can a day you would be eating about 28 oz in a week, which is over the limit. Pregnant women, women of child-bearing age, children, and people who don't weigh very much are at a higher risk. Some types of tuna have more mercury than others.