References

This page lists the research and reference material behind the numbers used on FitCalc, grouped by the topic they support. Each one comes with a plain sentence on what it actually shows — not a summary of the whole paper, just the part this site relies on.

Some of the numbers on this site are direct research findings. Others, like the 3,500-calorie-per-pound rule, are long-standing industry conventions rather than the output of one study, and are labelled that way below rather than dressed up as something more precise than they are.

Energy expenditure and calorie estimates

• A new predictive equation for resting energy expenditure in healthy individuals. Mifflin MD, St Jeor ST, et al. (1990). American Journal of Clinical Nutrition 51(2):241–247. PubMed.

  What it supports: the equation the TDEE and calorie-target calculator uses to estimate resting energy expenditure from height, weight, age and sex.

• Caloric equivalents of gained or lost weight. Wishnofsky M. (1958). American Journal of Clinical Nutrition 6(5):542–546. PubMed.

  What it supports: the origin of the "3,500 calories per pound" (about 7,700 kcal per kilogram) rule this site uses to turn a calorie deficit into an expected rate of fat loss. This is an industry convention traced back to this one paper, not a modern measurement.

• What is the required energy deficit per unit weight loss? Hall KD. (2008). International Journal of Obesity 32(3):573–576. DOI.

  What it supports: why the 3,500-calorie rule above is only an approximation — it overstates the deficit actually needed once someone is already fairly lean, rather than being a fixed constant that applies the same way at every body-fat level.

• Discrepancy between self-reported and actual caloric intake and exercise in obese subjects. Lichtman SW, et al. (1992). New England Journal of Medicine 327(27):1893–1898. DOI.

  What it supports: people who reported eating under 1,200 kcal a day and were not losing weight had under-reported what they actually ate by 47% on average and over-reported their exercise by 51% — the cause was inaccurate tracking, not a broken metabolism.

Protein

• International Society of Sports Nutrition position stand: protein and exercise. Campbell B, et al. (2007). Journal of the International Society of Sports Nutrition 4:8. DOI.

  What it supports: one of the two ISSN position-stand papers behind the protein target calculator's working range for people who train regularly.

• International Society of Sports Nutrition Position Stand: protein and exercise. Jäger R, et al. (2017). Journal of the International Society of Sports Nutrition 14:20. DOI.

  What it supports: the updated ISSN position stand — the more recent of the two papers this site's protein guidance is built on.

• Dietary protein for athletes: from requirements to optimum adaptation. Phillips SM & van Loon LJ (2011). Journal of Sports Sciences 29:S29–38. DOI.

  What it supports: the case for the upper half of this site's protein range for strength and hypertrophy training, and for requirements shifting with training goal and energy balance.

• Protein requirements are elevated in endurance athletes after exercise as determined by the indicator amino acid oxidation method. Kato H, et al. (2016). PLoS ONE 11(6):e0157406. DOI.

  What it supports: the endurance-athlete figure in this site's protein guidance — measured requirements higher than general population guidelines suggest.

• Timing and distribution of protein ingestion during prolonged recovery from resistance exercise alters myofibrillar protein synthesis. Areta JL, et al. (2013). The Journal of Physiology 591(9):2319–2331. DOI.

  What it supports: spreading protein across several meals beats getting the same daily total from one or two large doses — the reasoning behind this site's per-meal split.

• Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Moore DR, et al. (2009). American Journal of Clinical Nutrition 89(1):161–168. PubMed.

  What it supports: the roughly-20-gram per-dose figure behind the advice to split a daily protein target into several meals rather than fewer, larger ones.

Fat

• ISSA Nutrition Coach Textbook, Chapter 6 (Fats), "Recommended Dietary Allowances" — certification course material.

  What it supports: the 20%-of-calories fat floor the TDEE calculator uses for its macro breakdown, and the 15–20% range the IOC recommends for high-activity athletes. This is Coach Ohm's own ISSA certification textbook, not a public paper, so no external link is available — the edition is not listed here yet and will be added once confirmed.

• PESA Sport Nutrition course materials — certification course material.

  What it supports: the 10–20 g/day absolute fat floor used when a calorie target is tight enough to trim fat toward its hard floor, and the roughly 11 g-per-meal minimum for fat-soluble vitamin absorption. Course material from Coach Ohm's PESA certification, not independently linkable — the exact course title and date are not listed here yet and will be added once confirmed.

Carbohydrate

• ISSA Strength & Conditioning Part 2, Chapter 21 (Nutrition), Table 21.3 "Macronutrient Requirements Based on Activity Level" — certification course material.

  What it supports: the carbohydrate-by-training-volume ranges the TDEE calculator's macro breakdown uses to fill remaining calories after protein and fat are set (roughly 3–12 g/kg depending on training load). Coach Ohm's own ISSA certification textbook, not independently linkable — the edition is not listed here yet and will be added once confirmed.

Dieting, diet breaks, and metabolic adaptation

• Intermittent energy restriction improves weight loss efficiency in obese men: the MATADOR study. Byrne NM, Sainsbury A, King N, et al. (2018). International Journal of Obesity 42:129–138. DOI.

  What it supports: in this trial, eight alternating two-week blocks of restriction and maintenance beat continuous restriction on both weight and fat loss. Said plainly: the diet-break spacing this site uses is a practical adaptation of that logic, not the MATADOR protocol itself — the study used two-week blocks in already-lean men, this site spaces breaks further apart depending on how much fat there is to lose.

• Attenuating the biologic drive for weight regain following weight loss: must what goes down always go back up? Melby CL, et al. (2017). Nutrients 9(5):468. DOI.

  What it supports: the mechanisms behind why energy expenditure falls during a diet and which part of that drop is temporary rather than permanent.

Strength

• Essentials of Strength Training and Conditioning, 3rd ed. Baechle TR & Earle RW (eds), National Strength and Conditioning Association (2008). Human Kinetics. Open Library. ISBN 9780736058032.

  What it supports: the %1RM-by-repetitions table behind the working weight calculator. Its published data runs to about 12 repetitions — the 15, 18 and 20-rep rows on this site extend that same pattern beyond what the table itself covers, which is worth knowing if you are working at the higher end.

What this page is not

Not every sentence on FitCalc traces back to a citation on this list. A lot of it is standard coaching practice rather than a specific research finding, and dressing that up with a citation it doesn't have would be the same overreach this site was built to avoid. None of the research above was conducted by Coach Ohm or FitActo — it is the published work of the researchers named, read and applied here rather than produced here.

Found a citation that looks wrong, a link that doesn't work, or a claim that should be sourced and isn't? contact@crafnia.com — corrections are welcome.