How we calculate

Your resting energy expenditure is estimated with the Mifflin-St Jeor equation, using your weight, height, age and sex:

Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Source: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. “A new predictive equation for resting energy expenditure in healthy individuals.” The American Journal of Clinical Nutrition, 1990;51(2):241–247. Read on PubMed

Your resting energy is multiplied by a physical activity level factor based on the activity you report during onboarding, to estimate total daily energy expenditure.

Source: FAO/WHO/UNU Expert Consultation. Human Energy Requirements, FAO Food and Nutrition Technical Report Series 1, Rome, 2004, which defines the physical activity level (PAL) values used for this kind of estimate. Read the report

Your daily calorie target is your estimated daily energy needs minus a deficit sized to the pace you chose. Timeframe estimates assume roughly 7,700 kcal per kilogram of body tissue lost, which is a planning approximation rather than a guarantee. Real weight change is not linear: energy expenditure falls as you lose weight, so early progress is usually faster than later progress.

Source: Hall KD, Sacks G, Chandramohan D, Chow CC, Wang YC, Gortmaker SL, Swinburn BA. “Quantification of the effect of energy imbalance on bodyweight.” The Lancet, 2011;378(9793):826–837. Read on PubMed

On a safe pace of weight loss, see the UK National Health Service guidance of about 0.5 to 1 kg per week. NHS healthy weight

Macro suggestions favour a higher protein intake during a calorie deficit, which the evidence associates with better retention of lean mass.

Source: Jäger R, Kerksick CM, Campbell BI, et al. “International Society of Sports Nutrition Position Stand: protein and exercise.” Journal of the International Society of Sports Nutrition, 2017;14:20. Read the position stand