Method
Sources
Every figure on this site comes from a published source or a stated rule of thumb. These are the published sources behind every figure. Last checked 21 October 2026.
Energy and body size
- Mifflin MD, St Jeor ST and others. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990.
- World Health Organization. Adult BMI classification, and the expert consultation on BMI in Asian populations.
- Activity factors and the 550 kcal a day for about 0.5 kg a week rule: commonly used estimates, not measurements of any person.
- 1 kcal = 4.184 kJ: the definition of the thermochemical calorie.
Protein and water
- National Health and Medical Research Council (NHMRC). Nutrient Reference Values for Australia and New Zealand: protein recommended dietary intake and water adequate intake.
- 1.6 g of protein per kg for people who train: a commonly used figure, not a requirement.
Food labels
- Food Standards Australia New Zealand (FSANZ). Nutrition information panel requirements, including the 8,700 kJ average adult daily intake used as a reference.
- Australian Government. Health Star Rating system.
Sleep and habits
- Sleep Health Foundation (Australia). Sleep needs across the lifespan.
- National Sleep Foundation (US). Recommended sleep durations.
- Lally P, van Jaarsveld CHM, Potts HWW, Wardle J. How are habits formed: modelling habit formation in the real world. European Journal of Social Psychology, 2010.
- BJ Fogg, Tiny Habits, and James Clear, Atomic Habits (2018), for the cue and habit stacking ideas.
- The 90 minute sleep cycle and 15 minutes to fall asleep: commonly used rules of thumb.
How we use them
See how we calculate for the exact formulas. If you find an error, please tell us through the contact page.