How do I log my weight in Base?

Open the bodyweight screen from the dashboard's weigh-in habit card, the Food Log shortcuts menu, or Settings. It opens pre-filled with your current trend weight, with steppers either side moving in 0.2 lb increments. Adjust and save — the number pad is there but usually unnecessary.

Why is the weight field pre-filled?

Because tomorrow's weight is almost always within a pound of today's trend, so pre-filling turns typing into confirming. Every input in the app that can be pre-filled from history is, on the principle that you should be confirming numbers rather than entering them.

Does it matter what time of day I weigh in?

Consistency matters more than the specific time. Trend weight smooths random noise well but cannot remove a systematic shift, so weighing before breakfast on some days and after dinner on others introduces a bias the smoothing will faithfully preserve. Pick a time and keep it.

Can I log a weight for a past day?

The screen logs to today. For a missed day, the trend carries forward over calendar days rather than jumping, so a gap costs less than it would in a naive average — the correct response to a missed weigh-in is to weigh in today rather than to reconstruct yesterday.

What is the weigh-in habit grid on the dashboard?

The last seven days, showing which ones you weighed in on, with a count. It only counts real weigh-ins — synthetic demo data is tagged separately and deliberately excluded, because a habit grid that claims you stood on a scale forty-six days running because a seed function said so would be worthless.

Log Your Bodyweight in Two Taps

Two taps, by design

The bodyweight screen. Pre-filled with the trend, steppers either side at 0.2 lb, and the number itself tappable when the reading is further off than a few taps.

The screen exists to satisfy a rule that runs through the app: the three daily actions — log the standard day of food, log a set, log bodyweight — should each take two taps.

Pre-filling is what makes that possible. Tomorrow's weight is almost always within a pound of today's trend, so the pre-filled value turns typing into confirming. The steppers cover the normal case; the number itself is tappable for the morning after a long flight.

Where to open it from

The weigh-in habit card on the dashboard
The Food Log's shortcuts menu, under Weight
Settings, Log Bodyweight

The habit card is the intended route, because it is the one that also tells you whether you have been doing it.

Weigh consistently

Trend weight smooths random noise well. It cannot remove a systematic shift, and that distinction is the whole of the practical advice.

Weighing before breakfast some days and after dinner on others does not average out — it introduces a bias the smoothing will faithfully preserve and pass on to every rate calculation downstream.

So: same point in the day, same conditions. First thing, after the bathroom, before food and drink, is the conventional choice because it is the most repeatable state a day contains.

Habit	Effect on the trend
Daily, same time	Best case. Converges fast, noise cancels.
Daily, varying times	Noise plus a bias that does not cancel
Weekly, same time	Workable but slow to detect a real change
Sporadic	The trend carries gaps forward; rate estimates get noisy

What a missed day costs

Less than you would think. The trend runs over calendar days with gaps carried forward rather than over the sparse list of weigh-ins, so a missed day does not compress into a step change when you return.

The correct response to a missed weigh-in is to weigh in today. Reconstructing yesterday from memory adds a fabricated data point to a series whose entire value is that it is measured.

The habit grid

The dashboard's weigh-in card shows the last seven days with a count, and tapping it comes straight here.

It counts real weigh-ins only. Synthetic history used for demonstration is tagged separately and excluded, because a grid claiming you stood on a scale forty-six days running because a seed function said so would be worse than no grid.

Why this is the highest-leverage thirty seconds in the app

Weigh-ins are the input to the feedback loop that makes the calorie target yours rather than a formula's:

maintenance = average logged intake − (trend change × 3500 ÷ days)

No weigh-ins, no trend. No trend, no measured maintenance — the app falls back to a Mifflin-St Jeor prediction and labels it as an estimate, which is honest and much less useful.

Food logging and weighing in are the two habits that make everything else work, and weighing in is by far the cheaper of the two.

Common mistakes

Skipping the weigh-in because the number will be high. Sodium, carbohydrate and travel move water. A high reading is data; a missing one is a hole in the series.

Weighing after eating. Adds a large, inconsistent offset.

Weighing weekly and reading each reading as a change. One noisy sample per week cannot separate signal from noise.

Reconstructing a missed day. Fabricated points corrupt the one thing the series has going for it.

Reacting to a single morning. Trend weight exists precisely so you do not have to.

Changing scales mid-block. Different scales disagree by a pound or more, and that shift will look like a real change.

What to do next

Weigh in tomorrow morning before eating and save it. Then do it for fourteen days straight — that is the point at which the trend line becomes genuinely more informative than the number on the scale.