The Diet plan is designed to give you a balanced approach to eating by first determining your energy needs and then splitting those calories into macronutrients: carbohydrates, proteins, and fats. Our calculations account for your basal metabolic rate (BMR), your total daily energy expenditure (TDEE), and any desired weight change (in kg/week). This transparency ensures you understand how your calorie and macro targets are set—and the formulas used are backed by authoritative research from peer-reviewed journals and respected health institutions.
We use the Mifflin-St Jeor equation (validated by recent studies) for estimating BMR, as published in the American Journal of Clinical Nutrition (1990):
BMR = (10 × weightkg) + (6.25 × heightcm) − (5 × age) + 5
BMR = (10 × weightkg) + (6.25 × heightcm) − (5 × age) − 161
A 30-year-old woman, 65 kg, 160 cm tall:
BMR = 10 × 65 + 6.25 × 160 − 5 × 30 − 161
BMR = 650 + 1000 − 150 − 161
BMR = 1,339 kcal/day
Source: Mifflin M.D. et al. (1990). American Journal of Clinical Nutrition, 51(2):241-7
Your TDEE adjusts the BMR by your activity level. We use these scientifically-validated multipliers from Healthline's research:
Little to no exercise
TDEE = BMR × 1.2
Light exercise 1-3 days/week
TDEE = BMR × 1.375
Moderate exercise 3-5 days/week
TDEE = BMR × 1.55
Hard exercise 6-7 days/week
TDEE = BMR × 1.725
For a BMR of 1,339 kcal and a "Moderately Active" lifestyle:
TDEE = 1,339 × 1.55 = 2,075 kcal/day
Source: Healthline – What Is Basal Metabolic Rate?
To achieve a weight loss of X kg per week, we adjust the TDEE by subtracting a caloric deficit. Based on research from Livestrong and Mayo Clinic, the rule-of-thumb is:
~7,700 kcal per kg of fat lost
This translates to approximately 3,500 calories per pound, which aligns with Mayo Clinic's recommendation of 1-2 pounds (0.45-0.9 kg) per week for safe weight loss.
Daily Deficit = (7,700 × kg/week target) ÷ 7
Calorie Target = TDEE − Daily Deficit
Harvard Health recommends not going below 1,200 kcal/day for women or 1,500 kcal/day for men without medical supervision.
If you aim to lose 0.5 kg per week:
Daily deficit = (7,700 × 0.5) ÷ 7 = 550 kcal
With TDEE = 2,075 kcal, the target becomes:
Calorie Target = 2,075 − 550 = 1,525 kcal/day
Sources: Livestrong – How to Lose Weight Fast, the Healthy Way; Harvard Health – Calorie Counting Made Easy
After setting your calorie target, we allocate calories among macros. Our recommendations align with the National Academies' Acceptable Macronutrient Distribution Ranges (AMDR) for a balanced diet:
AMDR range: 10-35%
4 kcal per gram
AMDR range: 20-35%
9 kcal per gram
AMDR range: 45-65%
4 kcal per gram
Protein:
0.3 × 1,525 = 458 kcal
458 ÷ 4 = 114 g
Fat:
0.3 × 1,525 = 458 kcal
458 ÷ 9 = 51 g
Carbs:
0.4 × 1,525 = 610 kcal
610 ÷ 4 = 152 g
Source: Institute of Medicine / National Academies – Dietary Reference Intakes: Macronutrient Distribution
Applying these formulas to your daily life requires a systematic approach. Here's how to implement the Recommended Diet effectively:
Begin by accurately measuring your current weight, height, and determining your activity level. Use our formulas to calculate your BMR and TDEE as your baseline.
For weight loss, aim for 0.5-1kg per week (approximately 500-1000 calorie deficit daily). Harvard Health recommends not going below 1,200 kcal/day for women or 1,500 kcal/day for men without medical supervision.
Research from the FAO shows that BMR declines approximately 1-2% per decade in adults. Older adults should focus on higher protein intake (1.0-1.3g/kg/day) combined with strength training to preserve muscle mass.
Follow the National Academies' AMDR guidelines: 45-65% carbs, 20-35% fat, and 10-35% protein. For muscle building, research suggests higher protein intake of approximately 1.5-1.6g/kg/day is optimal.
Fill your plate with whole, unprocessed foods—lean proteins, whole grains, vegetables, fruits, and healthy fats. This not only helps you meet your macros but also provides essential micronutrients.
Regularly track your weight, energy levels, and how you feel. A small weekly adjustment (around 100–200 kcal) might be needed if you are not meeting your weight loss or gain targets.
Especially important if you're bulking or trying to preserve muscle as you lose weight. Aim for about 30% of your calories from protein. This supports muscle repair and growth.
Water is essential for overall health and aids in digestion and nutrient absorption. Aim for 2–3 liters per day, depending on your activity level.
Combine your nutritional strategy with regular physical activity. Strength training is crucial for muscle maintenance (especially for older individuals or those bulking), while cardio supports overall health and fat loss.
Although our formulas provide a robust starting point, individual needs vary. Consult with a nutritionist or healthcare provider before making drastic changes, especially if you have existing medical conditions.
Mifflin M.D. et al. (1990). A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr, 51(2):241-7 – Formulated the Mifflin-St Jeor BMR equations (men: 10×wt + 6.25×ht – 5×age + 5; women: ... – 161), which are used in our BMR calculation.
View on PubMedHealthline – What Is Basal Metabolic Rate? – Explains BMR and includes the standard physical activity multipliers for estimating TDEE (1.2 for sedentary, 1.55 for moderate, etc.).
Read on HealthlineLivestrong – How to Lose Weight Fast — the Healthy Way – References expert advice (Mayo Clinic) that safe weight loss is ~1–2 lbs per week, achieved with a 500–1000 calorie daily deficit. Supports our use of moderate caloric deficits for fat loss.
Read on LivestrongHarvard Health – Calorie Counting Made Easy (Apr 3, 2024) – Emphasizes not going below 1,200 kcal/day for women or 1,500 kcal/day for men without supervision. We adhere to this to ensure nutritional needs are met on the Recommended Diet.
Read on Harvard HealthInstitute of Medicine / National Academies – Dietary Reference Intakes: Macronutrient Distribution – Defines the AMDR for adults as 45–65% carbs, 20–35% fat, 10–35% protein. Our Recommended Diet macro recommendations align with these ranges for a balanced diet.
Read on Human NutritionNutrients journal (2015) – O'Connell et al., Protein Requirements and Recommendations for Older People – Finds that older adults benefit from higher protein intake (~1.0–1.3 g/kg/day) combined with exercise to preserve muscle and strength. This evidence underpins our higher protein suggestion for older users.
View on PMCMedical News Today – How much protein do you need to build muscle? (citing Nutrition Reviews 2020 and Sports Medicine 2022 meta-analyses) – Concludes that ~1.5–1.6 g/kg/day of protein is optimal for muscle growth, with gains plateauing beyond that. This supports our protein target for bulking individuals.
Read on Medical News TodayFood and Agriculture Organization (FAO) – Human Energy Requirements (2001) – Section 5.5 documents that basal metabolic rate declines ~1–2% per decade in adults and explains factors in metabolic slowdown. We factor in age in BMR and encourage counteracting muscle loss via strength training.
Read on FAOThis document provides a detailed, transparent explanation of how the Classic Diet calculates your calorie and macronutrient targets. By combining well-established formulas with best practices for nutritional health, we ensure that every user—from aged women managing weight to young men bulking up—receives scientifically-backed guidance. Our methodology is fully disclosed, meeting the rigorous standards set by Apple for health apps. This clarity helps you trust how your targets are derived and empowers you to make informed dietary decisions.