Fiber Target Methodology

Inputs and outputs

Formula

who_minimum_g = 25
demographic_reference_g = male 38, male over 50 30, female 25, female over 50 21, teen male 38, teen female 26
calorie_driven_g = (target_calories / 1000) * 14
lean_mass_adjustment_g = clamp((lean_mass_kg - sex_reference_lean_mass) * 0.12, -2, 4)
activity_adjustment_g = zone2 >= 180 ? 2 : zone2 >= 135 ? 1 : 0
metabolic_adjustment_g = goal == lose ? 2 : 0
recommended_g = round(clamp(max(who_minimum_g, demographic_reference_g, calorie_driven_g) + adjustments, 21, 50))
therapeutic_g = clamp(round(recommended_g + 10), 30, 50)

Calculation steps

1. Start with WHO minimum fiber and demographic reference targets.
2. Compare those with a calorie-density target of 14 g per 1000 kcal.
3. Add small adjustments for lean mass, activity, and fat-loss goal.
4. Clamp the result to a practical 21 to 50 g/day planning range.
5. Create a higher therapeutic reference by adding 10 g/day, capped at 50 g/day.

Guardrails

• Fiber should generally be increased gradually.
• People with gastrointestinal disease, swallowing issues, strict low-residue diets, or fluid restrictions need individualized clinical advice.

Sources

• Healthy diet World Health Organization
• Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Protein and Amino Acids National Academies Press