RUTINA

Health & nutrition sources

Last updated: October 29, 2026

Why this page exists

RUTINA is a fitness coaching and tracking app — not a medical service. Estimates for calories, macros, BMI, hydration, and meal nutrients are based on published formulas and public reference data. Links below let you verify those sources. Always confirm changes to training, diet, or medication with a qualified healthcare professional.

Sources we cite

  • A new predictive equation for resting energy expenditure in healthy individuals

    Mifflin MD, St Jeor ST, et al. Am J Clin Nutr. 1990

    Basal metabolic rate (BMR) used when estimating daily calorie targets from your height, weight, age, and sex.

    Open source

  • Calculate Your Body Mass Index

    National Heart, Lung, and Blood Institute (NHLBI / NIH)

    BMI formula and adult category cutoffs shown on the dashboard BMI card (underweight, normal, overweight, obese).

    Open source

  • Body mass index — BMI

    World Health Organization (WHO)

    International reference for adult BMI classification used alongside NHLBI guidance.

    Open source

  • International Society of Sports Nutrition Position Stand: protein and exercise

    Journal of the International Society of Sports Nutrition

    Protein target ranges used when splitting daily macros for active adults (roughly 1.4–2.0 g per kg body weight, personalized in-app).

    Open source

  • Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate

    National Academies of Sciences, Engineering, and Medicine

    Background for default hydration goals. The in-app water target is a personal tracking goal (default ~2.5 L), not a medical prescription.

    Open source

  • FoodData Central

    U.S. Department of Agriculture (USDA)

    Reference nutrient values (calories and macros per 100 g) used in meal suggestions and the food catalog where marked USDA-backed.

    Open source

  • Physical Activity Guidelines

    American College of Sports Medicine (ACSM) / related public guidance

    General context for activity and training recommendations. Workout calorie labels in the app are rough estimates for display only, not laboratory MET measurements.

    Open source

What is estimated vs measured

  • Daily calorie and macro targets start from Mifflin–St Jeor BMR, then apply activity and goal adjustments. You can edit targets in Profile.
  • BMI uses height and weight only; it does not measure body fat or muscle mass.
  • Water goals are personal tracking targets. The default (~2500 ml) is a convenient starting point informed by general hydration guidance, not a clinical prescription.
  • Workout “kcal” labels on session cards are rough display estimates from duration and exercise count — not calorimeter or heart-rate MET calculations.
  • AI Coach tips are general fitness coaching. They are not diagnoses or treatment plans. See also our Terms of Service (Health & fitness disclaimer).