Should I weigh daily or weekly during maintenance?

Daily, on the same scale at the same time, looking at the seven day rolling average instead of any single day. The National Weight Control Registry data is clear: about 75 percent of long-term maintainers weigh at least weekly, and a majority weigh daily. The reason daily beats weekly is statistical. Weight fluctuates by one to three pounds day to day from water, sodium, glycogen, and bowel timing, so a single weekly weigh-in can be off the trend by a lot. Daily readings averaged over seven days smooth that out and catch a real upward drift one to two weeks earlier than a weekly weigh-in does. The earlier you spot a drift, the smaller the correction. Weigh in the morning after the bathroom, before food or coffee.