I was going to ask the same about smoked mac, I have been having it quite a bit cos I THOUGHT it was free on EE. Thought it was just peppered mac that was syned. Thinking always gets me into trouble.
the mackerel is smoked slowly and a lot of the water evaporates leaving quite an oily fish. This then becomes smaller than in its normal state but each mouthful having lots of oil (all be it healthy oil). You would probably not manage a whole fresh mackerel but it would be quite easy to eat a couple of fillets when smoked. Think dried grapes (raisins) and you get the right idea xx