Activity Level is how much you move throughout your entire day - not just during workouts!

Think of it like this: Your body is like a car engine. Some days you're idling in traffic (low activity), other days you're cruising on the highway (high activity). Each burns different amounts of fuel (calories).

How to Choose Your Activity Level:

🪑 Low Activity (1.2x multiplier)

- You sit most of the day (office job, student, driver)

- You exercise 0-2 times per week or very lightly

- You take elevators, drive everywhere, relax in evenings

🚶‍♀️ Medium Activity (1.55x multiplier)

- You have a job where you stand/walk a lot (teacher, retail, nurse) OR

- You have a desk job but exercise 4-5 times per week

- You take stairs sometimes, walk during lunch breaks

🏃‍♂️ High Activity (1.725x multiplier)

- You have a physically demanding job (construction, cleaner) AND

- You still exercise 4+ times per week on top of that

- You're always moving, walking/biking places, very active weekends

💡 Pro Tip: When in doubt, choose the lower level. It's better to start conservative!

BMR (Basal Metabolic Rate) = The calories your body burns just to stay alive.

Imagine you stayed in bed all day doing absolutely nothing - no moving, no thinking hard, just breathing and having your heart beat. That's your BMR!

How BMR is Calculated:

We use the Mifflin-St Jeor equation (the most accurate formula):

- For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5

- For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161

Example: A 25-year-old man, 180cm tall, weighing 80kg: BMR = (10 × 80) + (6.25 × 180) - (5 × 25) + 5 = 800 + 1,125 - 125 + 5 = 1,805 calories

This means his body burns 1,805 calories per day just to keep him alive!

TDEE (Total Daily Energy Expenditure) = All the calories you burn in a complete day.

TDEE = BMR × Activity Level Multiplier

This includes:

- BMR (staying alive) - about 60-70% of total calories

- Daily activities (walking, standing, fidgeting) - about 15-30%

- Exercise - usually only 5-10% unless you're an athlete!

- Digesting food - about 8-10%

Example: Same guy from above with medium activity: TDEE = 1,805 × 1.55 = 2,798 calories per day

Target Calories = How many calories you should eat per day to reach your goal.

How Target Calories Are Calculated:

For Weight Loss: TDEE × 0.8 (20% less than you burn)

- Example: 2,798 × 0.8 = 2,238 calories to lose weight

For Maintenance: TDEE (eat exactly what you burn)

- Example: 2,798 calories to stay the same weight

For Weight Gain: TDEE × 1.1 (10% more than you burn)

- Example: 2,798 × 1.1 = 3,078 calories to gain weight

Why these percentages?

- 20% deficit = sustainable weight loss (about 1-2 lbs per week)

- 10% surplus = controlled weight gain (mostly muscle, not fat)

Macros are the three main types of food that give you energy and help your body function.

Protein 💪

What it does: Builds and repairs muscles, keeps you full

How much: 4 calories per gram

Good sources: Chicken, fish, eggs, beans, protein powder

How we calculate it:

- Weight Loss: 30% of your target calories ÷ 4 = grams of protein

- Maintenance/Gain: 25% of your target calories ÷ 4 = grams of protein

Example (weight loss at 2,238 calories): 2,238 × 0.30 ÷ 4 = 168g protein per day

Fat 🥑

What it does: Hormone production, vitamin absorption, brain function

How much: 9 calories per gram (most calorie-dense!)

Good sources: Nuts, olive oil, avocado, salmon

How we calculate it:

- Weight Loss: 25% of target calories ÷ 9 = grams of fat

- Maintenance: 30% of target calories ÷ 9 = grams of fat

- Weight Gain: 25% of target calories ÷ 9 = grams of fat

Example (weight loss at 2,238 calories): 2,238 × 0.25 ÷ 9 = 62g fat per day

Carbohydrates 🍞

What it does: Quick energy for workouts and brain function

How much: 4 calories per gram

Good sources: Rice, oats, fruits, vegetables, potatoes

How we calculate it:

- Weight Loss: 45% of target calories ÷ 4 = grams of carbs

- Maintenance: 45% of target calories ÷ 4 = grams of carbs

- Weight Gain: 50% of target calories ÷ 4 = grams of carbs

Example (weight loss at 2,238 calories): 2,238 × 0.45 ÷ 4 = 252g carbs per day

Why These Percentages?

- For Weight Loss (30/25/45): Higher protein keeps you full and preserves muscle while losing fat.

- For Maintenance (25/30/45): Balanced approach for general health.

- For Weight Gain (25/25/50): More carbs provide energy for muscle-building workouts.