The standard for male models in New York lately is a height around 5'10" to 6'2", a jacket size of 38 to 40, and a waist around 31 to 33" in most cases. I am 6'1", I weigh just under 180 lbs, size 40 jacket, 15.5/34 shirt, and 32" waist and I have been doing a little bit of modeling. I feel that at this weight I am very healthy and lean and fit, but not too skinny, and most of the other guys that I know who model feel the same. I currently do a strenuous gym workout about 4 days a week and I eat what I want in reasonable portions. I sometimes do experience an extremely poor appetite and have to sort of force myself to eat something but I rarely feel tired.
A year ago I weighed almost 50 lbs more and I felt horrible. I didn't think that I looked bad, but I was always tired. Just a little bit of effort in hitting the gym regularly and eating a little bit less worked great for me. My motivation was simply to feel better, not to achieve some 'idealized' look, but that was not a bad side effect. To my surprise, I have found that I absolutely love working out. I feel sensational and absolutely glow after a good workout.
Based on the horrific problems of obesity, I really don't have a problem with promoting images of lean, sexy people. That's not a bad thing to encourage, we just need to be mindful of promoting healthy ways of achieving those looks and make sure that we have a safety net in place.