Question: 1 can tuna per day?
Answer: You should not eat canned tuna if you consume more than 24 oz. (680 g) of fish a week, according to Consumer Reports, because you may take in too much mercury. 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.