The fashion industry is rarely logical or rational, but they're probably not going to like a growing consensus in the scientific community: Namely, that it's better to be overweight than excessively skinny.
This doesn't mean that you're off the hook on exercise and eating right. Eating crap and sitting on the couch is still going to kill you. But it turns out that starving yourself and running for ten hours can also kill you.
Essentially, study after study indicates that if you've got a chronic disease, such as diabetes, being skinny is more likely to kill you than being overweight. But why?
First of all, the word "obese" is tricky to define. Many studies use the Body Mass Index, or BMI, which was developed by a Belgian social scientists in the 1800s with no medical training, to define it. The problem is that a bodybuilder is technically "obese" under the BMI because he's heavy. He may have health problems: Obesity, however, is almost certainly not one of them.
In other words, the obese person may actually be at a reasonable weight by other scientific measures. But we don't know, because there's no widely accepted method of measuring obesity other than... the BMI.
Secondly, it's not really clear how fat is too fat. I know people that could run me into the ground with little trouble, and they're not what you call rails. Plenty of people are overweight or obese and in good health. It's a riddle.
The problem is that people define healthy as a "look" when it's a set of habits. If you eat a healthy diet, get an hour of exercise a day, and avoid stress, you're doing a lot for your health. But science has also found that the body tends to cling to weight. On some level, we're still a species convinced a starvation period is right around the corner.
So what to do with this paradox? Simple: Eat a healthy diet, get exercise daily, and work on reducing your stress. Health isn't about looking good. Health is about feeling good, about being there for the people who love you, about having the energy to spare to hang out with friends. Develop good habits, and there are rewards waiting... even if they're nothing to do with looks.
Why do heavy people care about anorexic models? I think it's similar to an anorexic person justifying their behavior by looking at 500 lb people. The extreme is not illuminating. And if you're not sure if you're obese or underweight, you're probably long overdue for a checkup. Only a doctor can tell you if you're healthy or not and diagnose things unrelated to size, like an vitamin deficiency or a virus.
Part of the 'paradox' is the media and it seems you have as well have bought into the idea the obesity itself is an actual illness or condition (partly though the medical community does call it a disease). It's not really. Being obese puts you at risk for developing conditions in you that can lead to death, but simply being too fat doesn't kill you. It's the other effects that do it; hypertension which can lead to heart disease, diabetes, etc. Obesity only increases the risk of developing those conditions, not the indicator you have them, but many people think it is and that's why they think there is a paradox. I am not at all surprised there are obese people who are in excellent health.
TL;DR Obesity puts one at greater risk for being unhealthy, it is not the indicator of being unhealthy.
I don't disagree with you but I'm not sure I follow your logic. As you say, the state of being obese doesn't kill you, but obesity often leads to side effects that can have serious health consequences. The same is true for a number of other conditions, right? Diabetes itself doesn't kill you, but the effect it has on your body can. Hypertension itself doesn't kill you, but the effect that it has on your heart can. Both of these are considered illnesses or conditions. The definition of "disease" is just a condition that adversely affects health...how is that not true of obesity?
And yes, I would say the same thing about being thin to the point that you put unnecessary stress on your body.
Everyone's body has it's own natural 'setting' in regards to fat percentage. This means that as some eat healthy and exercise regularly their healthy strong body will convert the 'excess' muscle to fat to use as energy. I know weightlifters, boxers, marathon swimmers in which all get judged as unhealthy because of their size. Fat doesn't make you unhealthy. It can make you feel reluctant to get preventative healthcare because you don't want to hear again that you need to lose weight to solve all that ails you. It can exasperate exsisting problems - say a bum knee or bad back. Most health issues are genetic predisposition or lifestyle. Fat is a descriptor, not a lifestyle. Losing weight is a common side effect of eating less calories than you burn...not a guarantee. Many people who exercise regularly and eat healthy look fit, but I know many who do not. I also know many who look fit but never exercise and eat mostly junk...their health suffers and their doctors say it is just genetics. As for looking good? If you like yourself, feel happy, healthy, strong and sexy in your own skin there will be people who love the way you look...plenty of them. *steps off soapbox*