Nutriiya Health Score System

1. Overview of the Health Score System

TheNutriiya Health Scoreis a composite metric designed to evaluate a user’s daily adherence tonutrition and hydration goals. It uses aweighted multi-factor modelto calculate a final score between 0 and 100.

Instead of a simple pass/fail system, Nutriiya uses aLinear Deviation Penalty model, which rewards users for beingcloser to their targets, even if they don’t hit them exactly.

Core Formula

$$Score_C = W_C \times \max \left(0, 1 - \frac{|Actual - Target|}{Target} \right)$$

Where:

W₍C₎ = Weight assigned to the component
Actual= User’s logged value
Target= Recommended goal
The absolute difference ensures bothunder-consumption and over-consumptionreduce the score

Why this approach is effective

This model ensuresbalance over extremes.

Example (Calories target = 2000):

If intake = 1800 → Deviation = 10% → Score = 18/20
If intake = 2200 → Deviation = 10% → Score = 18/20

This means:

Overeating and undereating are treated equally
The system promotes optimal balance, not just minimum thresholds

2. Component Weights & Targets

The total Health Score is calculated using four key components:

Component	Weight	Target Source
Protein	30%	User profile (protein_per_day)
Calories	25%	User profile (calories_per_day)
Fiber	25%	User profile (fiber_per_day)
Water	20%	Weight-based calculation

Water Calculation

Water Target = Weight(kg) × 0.035

Data Normalization

To ensure consistency:

Non-numeric inputs (e.g., “Moderate hydration”) are converted into standard numeric values
This allows accurate scoring across all users regardless of input format

3. Health Score Classification

After calculating the total score, users are grouped into health bands for better understanding:

Score Range	Category	Meaning
90 – 100	Great	High alignment with all health markers
70 – 89.9	Better	Strong adherence; minor improvements needed
50 – 69.9	Good	Moderate consistency; improvement needed
0 – 49.9	Needs Improvement	Significant deviation from goals

4. Scientific Basis & Reference

The Nutriiya Health Score is inspired by the Healthy Diet Index (HDI), a validated framework used in clinical and research settings.

Key Alignments with HDI

Multi-Dimensional Evaluation
Focuses on nutrition quality and balance rather than a single metric
Proportional Scoring
Measures how closely users follow recommended targets
Weighted Importance
Higher emphasis on protein and fiber, aligning with modern research on satiety, metabolism, and gut health

Reference

Formation and Validation of the Healthy Diet Index (HDI) for Evaluation of Diet Quality in Healthcare
(Source: ResearchGate – Publication 349684350)

Summary

The Nutriiya Health Score is designed to:

Encourage consistency over perfection
Reward closeness to targets, not just completion
Provide a balanced and scientifically grounded evaluation of nutrition and hydration