Thyunda said:
I...don't see why it's such a bad thing to encourage people not to be obese.
I'll break it down into chunks
1) Discrimination, stigmatisation and bullying (which is what it is in the end) is not good for people's health. This misconception that you should mock, stigmatise, or belittle a fat person "for their own good" is beyond ridiculous. Studies - REAL studies that is, not ones sponsored by Weight Watchers or Kellog's, have shown that the stress of being constantly stigmatised by people for their weight breeds within people the same illnesses that are perceived as being "fat diseases", diabetes? Heart problems due to blood-pressure? All capable of being caused by stress. And the idea that pointing out someone's weight is an eye-opener to them... Well, do you really think fat people are walking around UNAWARE that they're fat? When they have TV, Films, Magazines, People On The Street, Friends, Family etc all pointing it out to them every day? You really think your one stupid comment is going to be the one to "save" them?
Bibliography
http://www.biomedcentral.com/1471-2458/8/128
http://ajph.aphapublications.org/doi/abs/10.2105/AJPH.2007.114769
fiercefatties.files.wordpress.com/2012/02/nichd-letter.pdf
2) Weight has nothing to do with your health. No, really. Remember how when you were a little kid you got told "people come in all shapes and sizes"? That's still true, it's just that the weight-loss industry is worth $68 billion dollars and it's very good for them to breed a culture of shame, fear, and hatred.
What you eat and how much you exercise is highly unlikely to determine how much you weigh, and in fact it has been shown from as early as 1959 that diet and exercise only cause weightloss in 5% of people, and even then only about 10% of it, so most obese people will still be obese at the end of that.
But here's the thing - eating well and exercising moderately for 30 minutes, 5 times a week completely eliminates all risk of the illnesses associated with obesity. It is possible to be fat and healthy. The idea that you're only healthy when you're thin is incredibly damaging to fat people AND thin people. This line of thinking cause people to go on extreme diets and exercise far too much - and yes, that is a thing - thus putting a strain on their body. You know those contestants of The Biggest Loser Michelle Obama thinks are such a good role-model? They shit, piss and puke blood when you're not looking.
It also causes thin people who don't eat well or exercise to assume that they're fine. In fact, all those "fat diseases"? Thin people who live poor lifestyles can run afoul of them too.
Bibliography
http://www.jabfm.org/content/25/1/9.abstract?etoc
http://www.youtube.com/watch?v=aUaInS6HIGo
http://www.nutritionj.com/content/10/1/9
http://www.rxpgnews.com/obesity/Adolescent_Dieting_May_Predict_Obesity_and_Eating__3907_3907.shtml
http://newsroom.ucla.edu/portal/ucla/Dieting-Does-Not-Work-UCLA-Researchers-7832.aspx
http://www.ncbi.nlm.nih.gov/sites/entrez/17469900
http://www.ncbi.nlm.nih.gov/sites/entrez/10449014
http://www.ncbi.nlm.nih.gov/sites/entrez/1580453
3) Creating a culture where weight is equated with health is seriously dangerous.
You know that scary "obese people are costing healthcare money!" rhetoric that gets thrown around? A fun fact: No matter what your cause of death or illness an obese person, it will get attributed to obesity. We're not the apocalypse you all think/hope we are.
But that's a symptom of a big, big issue - that all an obese persons' ailments are attributed to their obesity. Heart problems, diabetes, high blood pressure, strep throat (seriously), pretty much anything. So when a fat person goes to the doc with a problem, they will almost invariably be told to lose weight. What happens when a thin person goes to the docs with the same issues? They get actual, medically sound advice is what.
Bibliography:
yaleruddcenter.org/resources/upload/docs/what/bias/WeightBiasStudy.pdf
http://thinkexist.com/quotes/steven_blair/
thinkmuscle.com/health/obesity-health-metabolic-fitness/
http://www.nejm.org/doi/pdf/10.1056/NEJM198603063141003
http://danceswithfat.wordpress.com/2012/05/11/the-true-cost-of-fatties/
http://bigliberty.net/2012/05/11/other-reason-why-fat-person-cost-calculations-are-bogus/
In short, we need to focus on HEALTH, not WEIGHT. What is the actual point of saying "hey you, be less fat!" over "hey you, eat a balanced diet and exercise 30 minutes, 5 times a week!"? Well I can tell you the actual point; money, dear boy. But certainly not health.