📉 Weight Loss · 10 min read · Subtopic 4 of 5

The Trigger Rule

Regain is never a decision; it is a drift the scale stops noticing at 2 kg and starts dictating at 10. The trigger rule is the simplest maintenance device on this site: one fixed line, one scripted response, and the discipline to run both without negotiating. This page explains where the line comes from, why it sits at 2 kg (about 5 lb) above goal rather than anywhere else, and exactly what to do the week it fires — because a rule you have to design at the moment of alarm is not a rule.

🔎 Evidence Snapshot ★★★☆☆ Moderate — regular self-weighing is well tied to maintenance; the specific 2 kg threshold is a practical decision rule built on that evidence, not a trial endpoint

What the evidence supports

  • Continuing self-weighing is one of the most consistent predictors of keeping weight off.
  • Identified early, small weight gains are easier to reverse than the same gains found months later.
  • Early standardized responses to small regain outperform self-designed catch-up efforts in relapse-prevention research.

What remains uncertain

  • The 2 kg figure itself is a consensus design choice, not a measured threshold.
  • Which correction format — full return to tracking, or lighter checks — works best per person is not settled.
  • For some people, any weighing becomes anxiety; the rule has to be adapted, not abandoned, in those cases.

Evidence last reviewed: August 15, 2026. Conclusions may change as new research is published.

the two-kilo alarm

Why Relapse Is a Drift, Not a Decision

Nobody regains ten kilos on purpose. Regain is a sequence of quiet defaults: a travel week, a busier month, a dessert that returned, a weigh-in that quietly stopped happening. The problem with drift is not that it is inevitable — it is that it is invisible in time. The first two kilos are indistinguishable from water and from a normal Tuesday; by the time the change is obvious to the eye or the belt, the correction has become a whole new diet. The statistics page in this series shows what that path costs on average; the trigger rule is the instrument that makes the drift visible while it is still cheap to fix. It works because it separates the two jobs the scale used to do — telling you news and telling you what to do — and keeps only the second.

Product picks are generic categories, not brands. We may earn a commission on Amazon or iHerb purchases at no cost to you — this never changes our evidence conclusions. Full disclosure

Smart scale with body-composition estimates

Can make body-weight trends easier to observe; body-composition estimates may be used as a rough personal trend only.

⚠️ Bioimpedance estimates vary with hydration and device assumptions; frequent weighing can be unhelpful for people with eating-disorder risk or body-image distress.

Check price on Amazon →

Setting the Line at 2 kg / 5 lb

The threshold needs to clear the noise and stay within the range of easy correction, and 2 kg (5 lb) does both jobs. Day-to-day and even week-to-week weight swings of a kilo or more are ordinary — water, glycogen, and salt move the number around — so the line cannot sit so low that ordinary fluctuation triggers it. It must also sit low enough that the correction is a matter of weeks, not months: 2 kg above goal, on the weekly average, is an honest surplus you can remove in two to four weeks of disciplined eating. Push the line to 5 kg or 10 kg and the same drift stops being a tune-up and becomes the new dieting project the whole series is trying to prevent. The bands of a normal day, the trend window, and this line are one coherent instrument.

The Cost of Waiting, Measured in Effort

The Cost of Waiting: Effort to Correct vs How Much Was Regained
Relative correction effort at three regain depths on the weekly average. The bars are proportional to effort, not a measured scale — the point is the shape: the correction cost climbs far faster than the regained weight.
🚨 +10 kg back a whole new diet ⚠️ +5 kg back 2–3 months of dieting 🎯 +2 kg (the line) a 2–4 week mini-cut

Read the chart as a compounding argument. The weight difference between the top bar and the bottom is five-fold; the effort difference is not linear — it is the difference between a tune-up you can schedule around work and a project that reorganizes your quarter. The trigger rule exists to keep you in the bottom bar forever.

The Scripted Response, Step by Step

When the weekly average crosses the line, the response is already written. Nothing on this page requires judgment at 9 p.m.; it requires only that you run the script.

  1. 📊 Confirm on the weekly average. One reading over the line is a Tuesday. Two consecutive weekly averages at or above goal + 2 kg is the alarm — no single-day readings allowed to trigger it.
  2. 📉 Run a mini-cut, not a panic. Return to the deficit protocol for two to four weeks — a modest, planned calorie trim, not a crash and not a punishment. The deficit-measured series is the playbook.
  3. 🥚 Keep the anchors switched on. Protein stays at 1.6 g/kg, both weekly lifts stay, steps stay. The correction trims energy; it does not dismantle the structure.
  4. ⚖️ Watch the average return. Stay in the mini-cut until the weekly average is back at or below goal, then step back up to the band over a week or two.
  5. 📝 Write one line on the cause. A trip, a month of steady stress, a returning dessert. Not for blame — for pattern. If the same cause appears twice, it stops being an accident and becomes a design problem for the identity page to solve.

Two weeks to four weeks is the honest window for 2 kg. If it ever takes longer, the likely story is that the drift was bigger than the weekly average showed, or the trim was too gentle — the band page covers how to read that.

What the Rule Is Not

2 kg
(5 lb) above goal on the weekly average — the line
2–4 wks
the whole mini-cut — a tune-up, not a new diet
1×/wk
weigh-in, forever — the cheapest maintenance tool there is

🚨 Catch 2 kg now or face 10 kg later

This is the entire economics of the rule. The first two kilos are cheap; the tenth costs your next six months. The trigger rule is the device that makes sure you never pay for the tenth, because the second never gets a chance to compound in silence. Weigh on the fixed day, read the weekly average, and let the script run itself — the whole system takes about ninety seconds a week, and it is the highest-return ninety seconds in this protocol. For the relapse-prevention research that supports early, scripted responses to small lapses, the two-day rule under Habit Formation is the deeper treatment.

The Trigger Rule, in One Table

DecisionDoAvoidRationale
⚖️ What fires the alarm Two consecutive weekly averages at goal + 2 kg A single reading, or a panic weigh-in Noise-proof
🚨 The response The 2–4 week mini-cut from the deficit protocol A crash, a cleanse, or "I'll fix it in January" Calibrated and short
🥚 During the correction Keep protein, lifts, and steps on Dismantling the whole structure Correct, don't collapse
🔄 After the correction Step back to the band; log one cause line Staying in mini-cut mode indefinitely Return to the new normal
🏥 Special cases Adapt the rule with a clinician Running it unadjusted on disordered territory Clinician territory

Questions, Answered Briefly

The Bottom Line

  1. Regain is a drift, not a decision — the trigger rule exists to make the drift visible while it is still cheap to fix.
  2. The line sits at goal + 2 kg (5 lb) on the weekly average — clear of ordinary noise, small enough to correct in weeks.
  3. The response is scripted in advance — confirm on the average, run a 2–4 week mini-cut, keep the anchors, step back to the band.
  4. Correction cost climbs faster than the weight — catch the second kilo, and the tenth never gets a chance to arrive.

Related Topics

Sources & further reading