Answer:
Luke is probably a libertarian who is a staunch defender of individual rights but also of individual responsibility. For this reason, he thinks that people who are not responsible with their own bodies and either smoke, or get overweight, should pay more for health insurance, because their medical treatment are likely to be more costly.
Matthew is probably a progressive liberal, or a social democrat. He believes that the greater good of society is more important than personal responsibility. He thinks that overweight people or smokers should have a right to health insurance regardless of the state of their bodies.