Question: 1 can of tuna everyday?
Answer: Tuna are top predators, and as such they tend to sequester mercury in their tissues. 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.