“Your body, like all your property, should be yours to do with as you please so long as you do not harm the body or property of others without their permission,” writes Seavey.
That’s fine, but he left out the part about taking full responsibility for harm done to one’s own body (or property) while doing as one pleases. In our society, if someone suffers harm from making stupid decisions, property is taken from others without their permission in order to help the poor unfortunate.
That is why genuine libertarianism cannot operate in this society.
That would be covered under "harm to other's property".
Perhaps it isn't explicit in this article, but it's explicit in the Libertarian Party platform:
Individuals own their bodies and have rights over them that other individuals, groups, and governments may not violate. Individuals have the freedom and responsibility to decide what they knowingly and voluntarily consume, and what risks they accept to their own health, finances, safety, or life.
All persons are entitled to keep the fruits of their labor. We call for the repeal of the income tax, the abolishment of the Internal Revenue Service and all federal programs and services not required under the U.S. Constitution. We oppose any legal requirements forcing employers to serve as tax collectors.
But, you are correct: libertarianism is incompatible with "welfare", "Obamacare", and even "Medicare" and "Social Security". So, it would be difficult in today's society, with 47% dependent on one or more of these redistribution programs.