Daily Weigh-Ins vs. Weekly Weigh-Ins: Which Gives a Clearer Trend
Daily weigh-ins, averaged over a week, generally produce a more statistically reliable trend than a single weekly weigh-in, since averaging smooths out normal day-to-day fluctuation — but a single consistent weekly weigh-in is simpler and still effective for many people, as long as it's done at a consistent time and condition each week.
Both approaches can work well — the real question is which trade-off between data quality and simplicity fits a given person's habits and relationship with the scale better.
The case for daily weigh-ins with averaging
Because daily fluctuation is essentially random noise around the real underlying trend, averaging seven daily readings smooths that noise out far more effectively than a single reading, giving a statistically more reliable signal of actual progress from week to week.
The case for a single weekly weigh-in
A single consistent weekly weigh-in (same day, same time, same conditions) is much simpler to maintain and avoids the potential stress or fixation some people experience from seeing daily fluctuation — for someone who finds daily weighing counterproductive to their mindset, weekly weighing can be equally effective for tracking a real trend over time.
Which approach to actually choose
Daily-with-averaging gives more data and a statistically smoother trend line, at the cost of more frequent engagement with the scale. Weekly weighing is simpler and still effective as long as consistency (same conditions each time) is maintained — the better choice depends more on which approach someone will actually stick with consistently than which is technically more precise.