For example when healthcare is nationalized everybody feels a need to control what others eat because it's costing society (who are referred to as taxpayers usually) money when an individual is overweight.I disagree. The enlightened citizen takes pity on the individual who is compelled to make decisions that not only damage the individual's own health, but also the economic health and ultimately the actual physical health of neighboring citizens. An over-consumer is a parasite, not an activist for personal liberty. The individual who acts contrary to self-interest (by choosing to routinely avoid moderation) is not a beacon of individualism, but rather, an aberration of the natural order of things. Were such an individual to behave in such a way in a more primitive tribal culture, the individual would be culled from the society -- for the greater good. Or, such an individual would easily be dealt with by nature itself, saving the tribe the trouble.
-- ChristopherBurg, in response to Wendy McElroy's piece at Mises Daily
Unfortunately, today, it is impractical (not to mention morally dubious) for society to expel or eliminate parasitic or criminal individuals. So instead, we have to imprison, rehabilitate, or marginalize them. This is just one of the the many costs of an advancing civilization that can only be brought about practically by the shared sacrifice between members and the distribution of such costs amongst its peoples.
And so we can see that the utopia of anarcho-capitalism in a modern civilization is an unrealistic fantasy. Following such reasoning to its conclusion, the application of deified individual liberty can only result in a regressive reductionism that culminates in a reversion to primitive tribalism at best, and the extinction of the human species at worst.
True liberty arises from the enlightened projection of the primitive and natural morality of the ideal tribal society to the gross mass of civilization with all of its deviation and extraordination, tempered by the pragmatic morality of the equilibrium of universal self-interest.