Source: https://guthlabs.ai/docs/instruments/basal-metabolic-rate-weight-change-projector/mechanism/

instrument mechanism / verified-clean

# Basal Metabolic Rate → Weight Change Projector mechanism

The inspectable method record for Basal Metabolic Rate → Weight Change Projector, kept separate from implementation and qualification.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Model scope

The supplied honest label appropriately identifies the model as simplified, nonlinear in reality, adaptive, and not medical advice. Before release, define the signed input convention, duration-unit handling, rounding policy, and whether the product should be renamed or relabeled because BMR is not computed or used.

- The formula is a rough static approximation, not a universally exact conversion; 7700 kcal/kg is an assumed energy-density estimate and real weight change is nonlinear and adaptive.

- The instrument name claims Basal Metabolic Rate, but the supplied formula does not use BMR or any basal metabolic rate input.

- The sign convention for daily caloric deficit/surplus is unspecified. The formula requires a signed energy balance (surplus positive, deficit negative) to produce weight gain as positive and weight loss as negative; entering deficit as a positive magnitude would reverse the result.

## Units and conventions

- 7700 means approximately 7700 kilocalories per kilogram of body-weight change.

- Daily caloric balance is expressed in kcal/day.

- Duration must be converted to days before multiplication; 1 week is assumed to equal 7 days.

- A caloric surplus is positive and a caloric deficit is negative.

- Projected weight change is reported in kilograms, with negative values meaning weight loss and positive values meaning weight gain.

## Inspectable vector

One of 4 source-bound review vectors:

````
{
  "inputs": {
    "daily_caloric_balance_kcal_per_day": -500,
    "duration": 14,
    "duration_unit": "days"
  },
  "expected_outputs": {
    "total_energy_delta_kcal": -7000,
    "projected_weight_change_kg": -0.9090909
  },
  "working": "1. Daily balance = -500 kcal/day. 2. Duration = 14 days. 3. Total energy change = -500 × 14 = -7000 kcal. 4. Projected weight change = -7000 ÷ 7700 = -0.9090909 kg."
}
````

## Failure boundary

**BREAK_CLAIMED** · SELF_FLAGGED

An extreme but syntactically numeric input causes JavaScript floating-point overflow during daily_caloric_balance_kcal × duration_days, producing Infinity and therefore no valid finite projected weight. The instrument should reject or explicitly flag the result.

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/basal-metabolic-rate-weight-change-projector/>)[03**Implementation**](<https://guthlabs.ai/docs/instruments/basal-metabolic-rate-weight-change-projector/implementation/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/basal-metabolic-rate-weight-change-projector/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`