You exercise. You lower your food portions. You eat healthy. You do everything you know you're supposed to do in order to shed some pounds. And yet, you step on the scale and, to your dismay, your weight doesn't go down; in some cases, it even goes up! Doesn't make any sense, does it? I have found myself in a similar conundrum over the years. Eventually, it dawned on me that my near-obsessive habit of drinking Diet Coke was probably working against me. When I probed even deeper, I realized that depriving my body of water was likely making it more difficult to lose weight. I mistakenly assumed that drinking more water would make your body retain more of it. But the exact opposite is true: The less water you drink, the more your body hoards whatever water you have in your system, thereby making you heavier.  I learned years ago that my dark yellow urine likely meant I was dehydrated. (A pale color with a tinge of yellow, on the other hand, suggests the bod...