Health Calculation Resources and Citations
Body Mass Index (BMI)
Body Mass Index (BMI) is a screening tool used to identify potential weight problems in adults. It is not a diagnostic tool but can indicate whether an individual is underweight, normal weight, overweight, or obese.
Formula Used
BMI = weight (kg) / [height (m)]²Primary Source
World Health Organization (WHO) & Centers for Disease Control and Prevention (CDC)
Real World Example: Sarah
“Imagine Sarah, who is 1.65m (5'5") tall and weighs 70kg (154lbs).”
Sarah's BMI is 25.7, placing her in the 'Overweight' category. While not perfect, this suggests she might benefit from a balanced nutrition plan.
BMI categories help healthcare providers assess the risk for chronic diseases. Higher BMI is correlated with increased risk of heart disease, high blood pressure, type 2 diabetes, and other health conditions.
| Category | BMI Range (kg/m²) |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obesity | ≥ 30 |
Total Daily Energy Expenditure (TDEE)
TDEE represents the total number of calories your body burns in a day, including basal metabolic rate (BMR) and physical activity.
Formula Used: Mifflin-St Jeor Equation
BMR (Men) = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5
BMR (Women) = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161*Where weight is in kg, height in cm, and age in years.
Activity Factors (Multipliers)
| Activity Level | Multiplier |
|---|---|
| Sedentary (little or no exercise) | x 1.2 |
| Lightly active (light exercise 1-3 days/week) | x 1.375 |
| Moderately active (moderate exercise 3-5 days/week) | x 1.55 |
| Very active (hard exercise 6-7 days/week) | x 1.725 |
| Extra active (very hard exercise & physical job) | x 1.9 |
Real World Example: Sarah's Burn
“Sarah is 30 years old, 70kg, and exercises 3 times a week (Moderately Active).”
Sarah burns approximately 2,263 calories every day just by living and exercising. This helps us set her baseline.
Why it matters
We use TDEE to calculate personalized calorie goals. For weight loss, we recommend a consistent deficit from your TDEE (typically 300-500 kcal) to promote sustainable fat loss.
Primary Source
Mifflin, M. D., et al. 'A new predictive equation for resting energy expenditure in healthy individuals.' The American Journal of Clinical Nutrition (1990).
Calorie Goals & Adjustments
Your daily calorie target is calculated by applying a surplus or deficit to your TDEE based on your specific goal.
Calculation Logic
Target = TDEE +/- Goal AdjustmentGoal Strategies
- •Weight Loss: We apply a deficit of 300-500 kcal/day (or approx. 20% of TDEE) to promote safe, sustainable fat loss.
- •Maintenance: Target equals TDEE to maintain current body weight.
- •Muscle Gain: We apply a surplus of 200-300 kcal/day (or approx. 10% of TDEE) to support tissue growth without excessive fat gain.
Real World Examples: Goal Adjustments
Protein Targets
Protein is essential for muscle repair, immune function, and satiety.
Calculated As
1.6g - 1.8g per kg of BodyweightSignificance
We use a sliding scale based on your goal. During weight loss phases, protein is increased (1.8g/kg) to preserve lean muscle mass and control hunger. For maintenance or gain, 1.6g/kg is sufficient for most individuals.
Real World Example: Muscle Protection
“Since Sarah is in a calorie deficit, she needs extra protein to protect her muscle.”
Sarah aims for 126g of protein daily. This equals 504 kcal (126g × 4 cal/g) and keeps her feeling full.
Dietary Fats
Fats are crucial for hormone production and nutrient absorption.
Calculated As
25% - 30% of Total CaloriesSignificance
We generally allocate 25% of your daily calories to fats. On 'Rest Days', this may increase to 30% as part of a carb-cycling strategy to improve metabolic flexibility.
Real World Example: Hormonal Health
“We allocate 30% of her 1,750 calorie budget to healthy fats.”
525 kcal represents about 58g of fat (525 ÷ 9 cal/g). Sarah fills this with avocados, olive oil, and nuts.
Carbohydrates
Carbohydrates are the body's primary fuel source for high-intensity activity.
Calculated As
Remainder of Calorie BudgetSignificance
After prioritizing protein (for structure) and fats (for hormones), the remaining calories are allocated to carbohydrates to fuel your workouts and daily activity. Carbs = Total Calories - (Protein Kcal + Fat Kcal).
Real World Example: Fueling Workouts
“The remaining calories in Sarah's budget go to carbohydrates.”
721 kcal equals roughly 180g of carbs (721 ÷ 4 cal/g). This allows Sarah to eat rice, oats, and fruit to fuel her gym sessions.
Added Sugar Monitor
The Sugar Monitor tracks your intake of 'Added Sugars'—sugars added to foods during processing or preparation—which are linked to negative health outcomes when consumed in excess.
Daily Limit
Men: <36g | Women: <25gSignificance
We follow the strict American Heart Association (AHA) guidelines. Unlike total sugars (which include fruit), added sugars significantly impact insulin resistance and weight. We alert you when you reach 70% (Warning) and 100% (Exceeded) of your daily limit.
Real World Example: Sarah's Alert
“Sarah (Female) has a limit of 25g of added sugar per day.”
At 20g, Sarah is at 80% of her limit. Her Sugar Monitor turns 'Orange' (Warning Zone), signalling her to choose zero-sugar options for dinner.
Breakfast Goal
The breakfast calorie goal helps distribute your energy intake to fuel your morning activity without spiking insulin excessively.
Calculated As
25% of Daily Calorie TargetSignificance
We allocate 25% of your daily calories to breakfast. This provides sufficient energy (glycogen) to wake up your metabolism but leaves room for larger meals later in the day when hunger typically peaks.
Real World Example: Sarah's Morning
“Sarah has a daily goal of 1,750 calories.”
Sarah aims for ~438 kcal for breakfast. This might be oatmeal with protein powder and berries.
Lunch Goal
Lunch is typically the largest caloric event to fuel the steepest part of your daily activity curve.
Calculated As
35% of Daily Calorie TargetSignificance
We allocate 35% of your calories here. Mid-day is often when insulin sensitivity is high and body temperature peaks, making it an ideal time for your largest meal.
Real World Example: Sarah's Power Lunch
“Sarah needs energy to get through her work afternoon and evening workout.”
Sarah aims for ~613 kcal for lunch. A large chicken salad with quinoa and avocado fits perfectly.
Dinner Goal
The dinner goal provides nutrients for overnight recovery while preventing late-night calorie surplus.
Calculated As
30% of Daily Calorie TargetSignificance
We allocate 30% to dinner. This is slightly less than lunch to account for the reduction in physical activity as you prepare for sleep, promoting better digestion and sleep quality.
Real World Example: Sarah's Recovery Meal
“Sarah needs enough food to not wake up hungry, but not so much she feels heavy.”
Sarah aims for ~525 kcal for dinner. Grilled salmon with asparagus and a small sweet potato.
Snack & Buffer
This buffer allows for small snacks between meals or flexible calories.
Calculated As
10% of Daily Calorie TargetSignificance
We reserve 10% of your calories for snacks. This flexible 'buffer' prevents meal targets from being too rigid and allows for a pre-workout snack or small treat.
Real World Example: Sarah's Treat
“A small buffer for whatever the day brings.”
Sarah has ~175 kcal set aside. She uses this for a post-workout protein shake or a piece of dark chocolate.
daily Hydration Goal
Adequate water intake is vital for metabolism, performance, and digestion.
Formula Used
35ml per kg of Bodyweight + Activity AdderSignificance
Base needs are calculated at 35ml/kg. Additional water is recommended based on your activity level (e.g., +500ml for moderate activity) to replace fluid lost through sweat.
Real World Example: Hydration
“Calculating Sarah's water needs based on her 70kg frame and activity.”
2,450ml + 500ml = 2,950ml. Sarah should aim for about 3 Liters of water daily for optimal health.