I agree with you, Raerae, the models look very thin on the website. I don't see a big change with the runway models anywhere in regard to looking a more appropriate weight for their height.
In regard to McDonald's, I saw that documentary titled "Super size me". A man did a study on himself by eating all his meals at McDonald's. The study didn't go according to his time table, because he began having chest pains and his blood work went into a red zone in a short period of time.
In the beginning, the guy was a normal weight and healthy (according to his personal doctor). He was literally throwing up from trying to digest all of the super sized meals. As the course of the study continued, he found that he was beginning to have a craving for the food , gaining weight rapidly, and feeling depressed.
In regard to thinness, there is new information. Physicians used to think thin was healthier, but advanced testing is showing this may not always be the case. If someone is thin and does little to no exercise, they may be just bone and fat with no muscle. On advanced MRI screening, these inactive thin folks are showing they have fat hidden internally.
Nutritionist have long been preaching that people who are extremely overweight are considered nutritionally starved. If their diet is from too much simple carbohydrates and/or animal fats, they will be starved of vitamins, minerals, & protein.
Therefore, weight is a complex issue. Body weight index, blood work, advanced MRI pictures, and body fat ratio are shedding a light into the blurred world of what is called a healthy weight and what is perceived as healthy.