I weigh myself before I go to bed. In the morning, I've lost 2 pounds. What the heck happens while I sleep?
First, stop weighing yourself so often! Stanton recommends no more than once a week, preferably naked, after using the bathroom in the morning. As to the night/day discrepancies, chalk it up to water. “When you’re at rest, your body is detoxifying, filtering blood through your liver and kidneys,” says Stanton. “That’s why you have to go to the bathroom first thing in the morning.” One liter of water can weigh 2.2 pounds, “and it’s pretty easy to pee out a liter in the morning,” she says. Nighttime perspiration can also account for lost ounces. So you’re not losing two pounds of fat; you’re losing two pounds of fluids and those are easily replaced by the beverages you consume throughout the day.