Obese women consuming a hypocaloric diet with 71% of their daily energy as carbohydrate and 43% of it as sucrose had no trouble losing fat. "Results showed that a high sucrose content in a hypoenergetic, low-fat diet did not adversely affect weight loss, metabolism, plasma lipids, or emotional affect."
Moreover, all carbohydrates, as well as protein, stimulate insulin release, and insulin is not in itself problematic: http://weightology.net/weightologyweekly/?page_id=319
Reducing carbohydrate intake can be an effective weight loss method, but that doesn't mean that carbohydrates intake is uniquely responsible for obesity to begin with. http://wholehealthsource.blogspot.com/2011/08/carbohydrate-h...
All of the world's longest-lived populations consume carbohydrate as their primary macronutrient.