Bo — published by El Mehdi Chenfour · Effective date: June 29, 2026
This page explains how Bo calculates your daily calorie and macronutrient targets, and the published science those calculations are based on. It is the source for the "How these targets are calculated" links shown in the app next to your numbers.
General wellness information, not medical advice. These targets are estimates produced by standard population formulas — they are not a prescription. Always consult a qualified healthcare professional before changing your diet. See the Medical & AI Disclaimer.
1. Resting energy (BMR)
Bo estimates your Basal Metabolic Rate with the Mifflin-St Jeor equation, the equation most recommended for healthy adults:
where s = +5 for men and s = −161 for women (for an unspecified sex Bo uses the midpoint, −78).
2. Daily energy (TDEE)
Your Total Daily Energy Expenditure is your BMR scaled by an activity factor:
Sedentary × 1.2 · Light × 1.375 · Active × 1.55 · Very active × 1.725
Bo stores your target on the sedentary (×1.2) baseline and credits movement on top — from your real step count when Apple Health is connected (about 0.04 kcal per step for a 70 kg person, scaled by bodyweight), or from your stated activity level otherwise — so daily activity is never double-counted.
3. Calorie target
For weight change, Bo applies a daily calorie deficit or surplus based on the well-established estimate that ≈ 7,700 kcal equals about 1 kg of body fat. Your chosen weekly pace sets the size of that adjustment:
daily adjustment = (weekly rate in kg × 7,700) ÷ 7
Safety floor: Bo never prescribes below 1,500 kcal/day for men or 1,200 kcal/day for women, regardless of the chosen pace.
4. Protein, fat & carbs
Protein:1.6 g per kg of bodyweight — within the range supported for active individuals.
Fat:25% of total calories.
Carbohydrates: the remaining calories after protein and fat.
Energy per gram (Atwater factors): protein 4 kcal/g · carbohydrate 4 kcal/g · fat 9 kcal/g.
Sources
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
Jäger R, Kerksick CM, Campbell BI, et al. International Society of Sports Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20. pubmed.ncbi.nlm.nih.gov/28642676
U.S. Dietary Guidelines for Americans 2020–2025 — Acceptable Macronutrient Distribution Ranges. dietaryguidelines.gov
Wishnofsky M. Caloric equivalents of gained or lost weight. Am J Clin Nutr. 1958;6(5):542–546 — basis of the ≈7,700 kcal/kg estimate. pubmed.ncbi.nlm.nih.gov/13594881
Merrill AL, Watt BK. Energy value of foods: basis and derivation (Atwater factors). USDA Agriculture Handbook No. 74. ars.usda.gov