Not really as the glycemic index is flawed as most people eat a range of foods together but then one can hypothesise that the less processed form of potato would be more filling and so decrease chances of over eating. But then a counter argument could be protested as it is unknown to me if drinking water with mash potato would mix in the stomach, there by trapping water in the stomach much like thick soup does and so make one feel fuller.
Men's Health is highly flaws too but I plan to age like a fine wine by stuffing my face with foods rich in antioxidants, red wine being a source of antioxidants :D