I suppose the 'self-interest' of desiring a cigarette outweighs the 'self-interest' of preserving your health.
Reminds me of debating Bentham in high school. If the feeling of self-interest of a murderer acts upon is greater than the self-interest of someone not to be murdered, etc...
Maybe the point is not to reduce judgment to one qualitative idea.
One certainly doesn't smoke imagining it's for the benefit of others - if anything it's the selfishness of now against the benefit of future me.
aka discounting time value, or something like that. "the feeling i will get now by smoking this cigarette, though fleeting, is worth to me now than the chance of years more living, or a healthier late life, if i do not smoke it".