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The science behind the app

Tracking what you eat is only useful if the numbers behind it rest on published research. Cal Clark's calorie budget, nutrition targets, weekly pace, and macro splits follow the sources below. We will keep this page current as the app changes.

Last updated September 2026

Registration and App Setup

These are the sources we reference when we set a first calorie budget and nutrition targets during setup.

  1. Physiology | Body Mass Index

    Zierle-Ghosh A, Jan A. Physiology, Body Mass Index [Internet]. National Library of Medicine. StatPearls Publishing; 2023.

    ncbi.nlm.nih.gov/books/NBK535456

  2. Adult Weight Management Recommendations Summary: Assess Energy Needs

    Adult Weight Management Recommendations Summary - Assess Energy Needs 2014. www.andeal.org.

    andeal.org

  3. The Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report

    The Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. National Institutes of Health; National Heart, Lung and Blood Institute; 1998.

    nhlbi.nih.gov (PDF)

  4. 2020 - 2025 Dietary Guidelines for Americans

    2020 Dietary Guidelines | Dietary Guidelines for Americans [Internet]. Dietaryguidelines.gov. 2020.

    dietaryguidelines.gov

  5. International Society of Sports Nutrition Position Stand: Diets and Body Composition

    Aragon AA, Schoenfeld BJ, Wildman R, Kleiner S, VanDusseldorp T, Taylor L, et al. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 2017 Jun 14;14(1).

    doi.org/10.1186/s12970-017-0174-y

Weight loss and gain pace

These are the sources we use when we judge whether a weekly lose or gain pace matches typical published guidance. Typical loss is about 0.25 to 0.9 kg per week, about 1 to 2 lb, with a common first checkpoint of about 10% of current weight in 6 months. Typical gain is a modest surplus, about 0.25 to 0.5 kg per week. A target BMI under 18.5 is not treated as a usual healthy range. Daily calories stay within a floor and a cap. Faster rates stay available; we do not call them typical.

  1. The Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report

    The Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report. National Institutes of Health; National Heart, Lung and Blood Institute; 1998.

    nhlbi.nih.gov (PDF)

  2. International Society of Sports Nutrition Position Stand: Diets and Body Composition

    Aragon AA, Schoenfeld BJ, Wildman R, Kleiner S, VanDusseldorp T, Taylor L, et al. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 2017 Jun 14;14(1).

    doi.org/10.1186/s12970-017-0174-y

  3. Physiology | Body Mass Index

    Zierle-Ghosh A, Jan A. Physiology, Body Mass Index [Internet]. National Library of Medicine. StatPearls Publishing; 2023.

    ncbi.nlm.nih.gov/books/NBK535456

  4. 2020 - 2025 Dietary Guidelines for Americans

    2020 Dietary Guidelines | Dietary Guidelines for Americans [Internet]. Dietaryguidelines.gov. 2020.

    dietaryguidelines.gov

Daily calorie budget

These are the sources we reference when we estimate basal metabolic rate and activity for the daily calorie budget.

  1. A new predictive equation for resting energy expenditure in healthy individuals

    Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.

    pubmed.ncbi.nlm.nih.gov/2305711

  2. 2011 Compendium of Physical Activities: a second update of codes and MET values

    Ainsworth BE, Haskell WL, Herrmann SD, Meckes N, Bassett DR Jr, Tudor-Locke C, et al. 2011 Compendium of Physical Activities: a second update of codes and MET values. Med Sci Sports Exerc. 2011;43(8):1575-1581.

    pubmed.ncbi.nlm.nih.gov/21681120

Micronutrient Targets

These are the sources we reference when we set micronutrient targets in the app.

  1. Daily Values

    Daily Values. Nih.gov. Published 2026. Accessed July 8, 2026.

    dsld.od.nih.gov/daily-values

  2. Daily Value on the Nutrition and Supplement Facts Labels

    FDA. Daily Value on the Nutrition and Supplement Facts Labels. FDA. Published online March 5, 2024. Accessed July 8, 2026.

    fda.gov

Daily Goals Macronutrient Splits

These are the sources we reference when we set daily carbohydrate, protein, and fat splits.

  1. Dietary Guidelines for Americans 2020-2025

    United States Department of Agriculture. Dietary Guidelines for Americans 2020-2025. USDA; 2020. Accessed July 6, 2026.

    dietaryguidelines.gov (PDF)

  2. Description of the Acceptable Macronutrient Distribution Range

    Description of the Acceptable Macronutrient Distribution Range. Nih.gov. Published November 12, 2024. Accessed July 6, 2026.

    ncbi.nlm.nih.gov/books/NBK610333

  3. Evaluation of the Effect of Macronutrients Combination on Blood Sugar Levels in Healthy Individuals

    Basturk B, Koc Ozerson Z, Yuksel A. Evaluation of the effect of macronutrients combination on blood sugar levels in healthy individuals. Iran J Public Health. 2021;50(2):280-287.

    pmc.ncbi.nlm.nih.gov/articles/PMC7956086

  4. International Society of Sports Nutrition Position Stand: Diets and Body Composition

    Aragon AA, Schoenfeld BJ, Wildman R, et al. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 2017;14(1).

    doi.org/10.1186/s12970-017-0174-y

  5. ISSN Exercise & Sports Nutrition Review Update: Research & Recommendations

    Kerksick CM, Wilborn CD, Roberts MD, et al. ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition. 2018;15(1).

    doi.org/10.1186/s12970-018-0242-y

  6. Defining "Low-Carb" in the Scientific Literature: A Scoping Review of Clinical Studies

    Chacón V, Cara KC, Chung M, Wallace TC. Defining "low-carb" in the scientific literature: A scoping review of clinical studies. Critical Reviews in Food Science and Nutrition. 2024;65(10):1-10.

    doi.org/10.1080/10408398.2023.2300705

  7. Ketogenic Diets for Body Weight Loss: A Comparison with Other Diets

    Dyńka D, Rodzeń Ł, Rodzeń M, et al. Ketogenic Diets for Body Weight Loss: A Comparison with Other Diets. Nutrients. 2025;17(6):965.

    doi.org/10.3390/nu17060965

Questions or Feedback

If you have a question about a recommendation, or you want to suggest another source, write to us: support@calclark.app