Method & limitations

Useful estimates begin with honest assumptions.

NutriSignal is deliberately transparent about what each result means, how it was derived, and where a general equation stops being personally reliable.

BMI

weight (kg) ÷ height² (m)

A population-level screening ratio shown with reference ranges. It does not measure body composition.

Resting energy

Revised Harris–Benedict

Estimates basal metabolic rate using age, equation sex, height, and weight—the method used by the original project.

Daily energy

BMR × activity factor

Applies a standard multiplier from 1.2 to 1.9, then adds a modest goal adjustment.

Daily targets

25% · 45% · 30%

Illustrative protein, carbohydrate, and fat distribution plus a 35 ml/kg hydration baseline.

Important context

What the model cannot know

Body composition. BMI cannot distinguish fat, muscle, bone density, pregnancy, or fluid changes.

Medical context. The equations do not account for medication, endocrine conditions, recovery, or eating-disorder risk.

Exact energy need. BMR and activity factors are statistical estimates; real energy expenditure can differ substantially.

Individual diet quality. Macro totals do not replace food variety, micronutrients, allergies, or culturally appropriate planning.

Project evolution

From beginner PHP project to adaptive web application.

The rebuild retains the original calculators and six-digit email-verification idea, while replacing MD5 passwords, hard-coded SMTP credentials, template leftovers, and fragile browser logic with Supabase Auth, validated TypeScript functions, tests, and responsive UI.

Try the model