Methodology

How HumanFuelGuide evaluates evidence, tests tools and supplements, and decides what to recommend: the evidence hierarchy, the product-testing window, food-database checks, and reviewer sign-off.

Evidence hierarchy

We prioritize systematic reviews, meta-analyses, and randomized controlled trials indexed on PubMed and the Cochrane Library over narrative reviews, mechanistic speculation, or secondary commentary. Where the evidence is preliminary, contested, or absent, we say so plainly rather than overstating confidence. Claims that rest on specific findings are cited to a resolvable DOI, not a self-published study.

Testing tools and apps

Calorie trackers, wearables, and training software go through a 30 to 90 day in-house evaluation. For trackers, we spot-check food-database entries against USDA FoodData Central, time real logging workflows, and note where databases mix verified and user-submitted data. We weight database accuracy and logging friction heavily because those are what determine real-world tracking quality.

Reviewing supplements

Supplement coverage is reviewed for mechanism, effective dosing, interactions, and evidence quality. We verify third-party batch testing (Informed Sport, NSF Certified for Sport, USP) before issuing a recommendation, and we separate supported effects from label marketing.

Authorship and review

Each domain is written by a specialty-matched member of the editorial board and medically reviewed by Greta Lindqvist, MS, RD, before publication. Every article carries published, updated, and last-reviewed dates and a named byline. Material reversals are logged on the updates page.

References

Core sources behind our evaluation approach. Each links to a resolvable DOI or primary dataset.

  1. Subar AF, Freedman LS, Tooze JA, et al. (2015). Addressing Current Criticism Regarding the Value of Self-Report Dietary Data. The Journal of Nutrition doi:10.3945/jn.115.219634
  2. Schoeller DA (1990). How Accurate Is Self-Reported Dietary Energy Intake?. Nutrition Reviews doi:10.1111/j.1753-4887.1990.tb02882.x
  3. Boushey CJ, Spoden M, Zhu FM, et al. (2017). New mobile methods for dietary assessment: review of image-assisted and image-based dietary assessment methods. Proceedings of the Nutrition Society doi:10.1017/S0029665116002913
  4. Burke LE, Wang J, Sevick MA (2011). Self-Monitoring in Weight Loss: A Systematic Review of the Literature. Journal of the American Dietetic Association doi:10.1016/j.jada.2010.10.008
  5. U.S. Department of Agriculture, Agricultural Research Service (2024). USDA FoodData Central. U.S. Department of Agriculture
Methodology | HumanFuelGuide