Could not be more wrong. Diet and weight training with the right amount of cardio is the best way to lose fat. I see a lot of skinny-fat people on the treadmill all the time, and they always look the same. 'Too much emphasis on low-intensity aerobic work. When most people think of fat loss, they think only of burning calories through cardio. While some aerobic activity will improve health and fitness levels and contribute to an energy deficit, too much cardio can lead to over-production of the catabolic hormone cortisol, which in turn leads to muscle loss and a soft, flabby appearance despite high levels of activity.' http://blog.gainfitness.com/2012/02/04/the-skinny-fat-syndrome-2/ 'A skinny fat person lacks lean muscle mass, which is one reason they have a high body fat percentage. If you've been dieting and doing cardio for years, you could be skinny fat. Lack of proper nutrition and too much cardio can break down your muscles, resulting in that soft, skinny fat appearance. Resistance training and proper nutrition, on the other hand, help to build and maintain muscle mass. Muscle helps the body burn fat because it requires more energy, even at rest. So the more muscle you have, the less fat.' http://sd-dickens.hubpages.com/hub/Are-You-Skinny-Fat-Heres-What-to-Do-About-It
I'm just trollin bro. 5'9" is just fine. In fact, that should be the slogan of all the 5-9ers. "I'm 5-foot-9 and that's just fine!"
If all you do is run on a treadmill and don't change it up in terms of running environment or maintain the same intensity/level of difficulty, chances are you're going to plateau and not see a difference in body fat. I run daily and do weight training every once in a while. Mostly body resistance push-ups/ body dips and I'm in pretty good shape. I'm 6'0 195 with a pretty solid frame and could be even leaner if I really took a hard-nosed approach on my diet -- I'll eat some chips or something fried here and there. My point is, yes, doing nothing but cardio could have a negative effect on you, as anything of too much can. But if you're to mix in weight training every once in a while, with an immaculate diet, but still sticking more to cardio, then that person would be in pretty damn good shape.
I lose a ton of weight when I alternate jogging and sprinting like a mofo on the treadmill. Kills my knees though.
cardio is for your cardiovascular health....I've gotten to 8% body fat before with absolutely no cardio