What the maintenance research shows
Long-term weight-maintenance registry studies consistently find that people who keep weight off for years report frequent self-weighing -- often daily or near-daily -- far more commonly than occasional or avoidant weighers.
Why frequent weighing seems to help
Frequent weigh-ins catch small upward trends early, while a pound or two is easy to address, rather than allowing gradual drift to accumulate unnoticed over months into a much larger regain.
The psychological objection, and the counterargument
Some worry daily weighing fosters anxiety or obsession over normal day-to-day fluctuation. The research-supported counter to this is tracking a rolling weekly average rather than reacting to any single day's number -- capturing the early-warning benefit without the emotional volatility of daily noise.
Building the habit
Weighing at a consistent time (morning, before eating, post-bathroom) and logging the number regardless of what it shows -- rather than only weighing on "good" days -- appears to be the version of this habit most associated with successful long-term maintenance in the research.