So why Wednesday?
1. When maintaining weight, Wednesday was found to have the least week-to-week fluctuations, so you'll get the most accurate reading by weighing in on Wednesday.
2. Wednesday also just so happened to be the day when people weighed the least each week.
Since we all tend to indulge more on the weekends, this makes perfect sense. You'll weigh the least and get the most accurate reading by weighing yourself smack dab in the middle of the week.