A few days ago, I figured I'd have some Mashed Potatoes...But, burn them off by doing alot of exercise. The exercise prevented me from gaining weight. But, an old "friend" paid a visit that night and the next day: Heart Burn. I've done this with fruit (more carbs, more exercise)...without the Heart Burn (and without weight gain). So, it must be something in starchy foods that gives me heart burn.