If you want to know why your diet isn't working, trainer Jim Karas says, keep a diary of every single random snack, licked spoon, broken cookie, and (oops!) 1,000-calorie meal.
You see the data. So many people over the years have said to me, "I really don't eat that much; I don't know why I've gained so much weight." But when they start keeping a food diary, the reality of what they're putting in their mouths—the sheer volume of what was previously inhaled unconsciously—is right there in black-and-white. It's astonishing, it's enlightening, and it's indisputable.
Our December issue features Oprah's Favorite Things—as well as your chance to win them all! You'll also find our easy holiday declutter plan, Dr. Oz's guide to sleeping better (starting tonight) and the ultimate holiday menu.