Nutrinaut publishing standard
Methodology and Sources
Source hierarchy, formula registry, validation rules, product heuristics and version history for every Nutrinaut tool.
Method standard
Transparent, deterministic and versioned
Calculator outputs are deterministic local calculations, not AI diagnoses. The same valid inputs produce the same result. Metric values are the canonical calculation path; pounds convert using 1 lb = 0.45359237 kg, feet using 30.48 cm and inches using 2.54 cm.
References support the method or context; they do not validate an individual result. Every numerical input is checked for a finite value inside a defensive product bound. Invalid values are rejected rather than silently clamped.
Source hierarchy
How evidence is selected
- Official standards and regulators. FDA, EFSA, EU regulations, USDA, NIH and other responsible public bodies.
- Professional consensus and systematic review. Used when the scope matches our recreational adult audience.
- Primary research. Used to establish an equation or clarify uncertainty, not to overgeneralise a single study.
- Product heuristics. Clearly labelled interface rules used for display or planning.
Formula registry
All eight methods
| Tool | Core logic | Canonical units | Display rounding | Version |
|---|---|---|---|---|
| Maintenance & Energy Needs | Mifflin–St Jeor REE; × FAO PAL range | kg, cm, years | Nearest kcal; range to nearest 10 | Energy 1.0 |
| Protein per Meal | Body weight × 1.2–1.6 or 1.4–2.0; ÷ meals | kg, g | Daily whole g; meals 0.1 g | Protein 1.0 |
| Workout Fuel Timing | Duration/intensity decision tree; contextual g/kg ranges | kg, minutes, hours | 0.1 g where useful | Fuel timing 1.0 |
| Nutrition Label Decoder | Serving multiplier or portion ÷ 100; amount ÷ DV/RI | servings, g, mg | Amounts 0.1; % whole | Labels 1.0 |
| Added Sugar & Drinks | Σ per-serving value × servings; sugar × 4 kcal/g | g, kcal | 0.1 g; whole kcal | Drinks 1.0 |
| Caffeine Dose & Timing | Σ mg; mg ÷ kg; circular time-to-bed difference | mg, kg, time | Whole mg; 0.01 mg/kg | Caffeine 1.0 |
| 7-Day Sleep Shortfall | Σ max(0, target − night); three-night trend | hours | 0.01 hour | Sleep 1.0 |
| Grocery & Meal Prep | Per-serving × servings × buffer − pantry; round to pack | user-selected units | 0.01 unit | Grocery 1.0 |
Label jurisdictions
US and EU/UK remain separate
US mode uses per-serving arithmetic and current adult/age-4+ Daily Values. EU/UK mode uses per-100 g or ml arithmetic and adult Reference Intakes. US added sugar is never inferred from an EU/UK “of which sugars” value, and salt is not compared directly with sodium.
Source register
The references behind each method
A new predictive equation for resting energy expenditure in healthy individuals
American Journal of Clinical Nutrition / PubMed · 1990 · Used by Maintenance & energy needs
Supports: Resting-energy equationHuman energy requirements: physical activity level
FAO/WHO/UNU · 2004 · Used by Maintenance & energy needs
Supports: PAL categories and uncertaintyNutrition and Athletic Performance
Academy of Nutrition and Dietetics, Dietitians of Canada and ACSM · 2016 · Used by Protein per meal
Supports: Active-adult protein ranges and meal contextExercise and Athletic Performance: Health Professional Fact Sheet
NIH Office of Dietary Supplements · Current · Used by Protein per meal
Supports: Athlete protein range and scopeInternational Society of Sports Nutrition position stand: nutrient timing
ISSN / PMC · 2017 · Used by Workout fuel timing
Supports: Short-turnaround recovery contextHow to understand and use the Nutrition Facts Label
US Food and Drug Administration · Current · Used by Nutrition label decoder
Supports: US serving and %DV interpretationRegulation (EU) No 1169/2011
European Union · 2011 · Used by Nutrition label decoder
Supports: EU declarations and Reference IntakesAdded Sugars on the Nutrition Facts Label
US Food and Drug Administration · Current · Used by Added sugar & drinks tally
Supports: Added-sugar definition and 50 g Daily ValueFoundation Foods documentation
US Department of Agriculture · Current · Used by Added sugar & drinks tally
Supports: General carbohydrate energy factor contextCaffeine topic and safety assessment
European Food Safety Authority · Current · Used by Caffeine dose & timing
Supports: Single-dose, daily and pregnancy reference valuesSpilling the Beans: How Much Caffeine is Too Much?
US Food and Drug Administration · Current · Used by Caffeine dose & timing
Supports: 400 mg context and variabilityRecommended amount of sleep for a healthy adult
American Academy of Sleep Medicine and Sleep Research Society · 2015 · Used by Sleep shortfall planner
Supports: Adult sleep-duration consensusSleep and heart-healthy living
National Heart, Lung, and Blood Institute · Current · Used by Sleep shortfall planner
Supports: Adult 7–9-hour public guidanceMeal planning, shopping and budgeting
USDA SNAP-Ed · Current · Used by Grocery & meal prep
Supports: Planning and budgeting contextLeftovers and food safety
USDA Food Safety and Inspection Service · Current · Used by Grocery & meal prep
Supports: 3–4-day leftovers guidanceHeuristic register
Rules we disclose rather than disguise
- Broad PAL ranges create a starting maintenance interval; they do not measure activity.
- Fourteen-day calibration and the ±0.25% trend band are planning heuristics.
- A caffeine dose of at least 100 mg within six hours of bedtime triggers a conservative context flag, not a sleep prediction.
- A ±0.25-hour sleep trend band labels a week as up, down or roughly steady.
- Grocery buffer and pack rounding are logistics choices, not nutrition recommendations.
Testing and correction
Reference fixtures before publication
Each calculation has a hand-checked reference fixture plus invalid, zero, negative, missing, extreme and unit-conversion cases. Tests reject NaN, Infinity, silent clamping and negative output where it cannot be meaningful. Editorial examples are recalculated when method code changes.
To report an error, include the URL, inputs, expected result, observed result and source if available. See the corrections workflow.
Version history
Launch register
Rebuilt the toolkit around eight whitelisted calculators, visible formulas, validated inputs and primary/official sources. Removed arbitrary scores and unsafe tool categories.