Can of tuna is only 28g protein, and you need at least 0.75g protein per Kg of body weight, so depends what else you ate in the day.
But - speaking from experience
the more the merrier if you don't want to feel hungry
(Eating more protein meant I lost weight without feeling hungry, so I can recommend it, even if you are happy with your weight *Wouldn't want to offend anyone, would I?*
)
I'm having gammon steak with the rest of the Cauliflower cheese and some runner beans from the garden.