Psychology are considered sciences or scientific

Psychology is considered a science. It uses the scientific method, can be falsified, and can give reliable results. Due the the nature of sociology it is a social science in that it has a 'positivist' school which uses statistics and such things as the scientific method, but also the 'interpretivist' school which relies upon field research and experience. Newsflash: I have an a-level (British qualification one gets in college which facilitates one's admittance to university)

humanities

Are subjects such as critical theory, literature studies, politics, philosophy, and whatnot. Newsflash: I am about to graduate, possibly with a first class degree, in one of those subjects and am about to start a Masters' degree.

People like him don't need advice or help

They obviously do.

They engage in willful self-deception to justify their poor choices and terrible lifestyle

Which could actually be a symptom of anything they might be suffering from. Besides, boogie has said before that he 'hates' every last inch of himself. Why would he choose a lifestyle in which he hates himself as much as people like yourself hate him?

They KNOW what they have to

And, because of people like you, they lack the drive to do so.

I have no interest in supporting someone, an entire class of people, that comprise approximately 67% (a total of 30% of our total population is considered obese) of our total population that are considered fat to the point of being unhealthy

Then you are part of the problem, not the solution.

They don't want to address facts and deal with reality

He knows he's unhealthy, he knows that if he does not succeed he could well die. Stop being an idiot and start listening. If you do not start listening then you will stay in your stupid, and futile, loathing.