Example Male: John

Meet John, an average American who is eager to optimize his nutrition for better health and fitness.

Step 1: Calculate Basal Metabolic Rate (BMR)

To get started, John needs to determine his Basal Metabolic Rate (BMR) – the number of calories his body needs at rest. Using the Mifflin-St Jeor equation, let's calculate his BMR:

John's weight: 180 pounds John's height: 6 feet (72 inches) John's age: 35 years

John's BMR = 66 + (6.23 × 180) + (12.7 × 72) - (6.8 × 35) = 1,979 calories/day

Step 2: Calculate Total Daily Energy Expenditure (TDEE)

Now, let's find John's Total Daily Energy Expenditure (TDEE) by multiplying his BMR with his activity level. John considers himself moderately active, so we'll use an activity factor of 1.55:

John's TDEE = 1,979 calories/day × 1.55 = 3,068 calories/day

Step 3: Determine Target Calories based on Goal

John's goal is to lose 1 pound per week, so he needs to create a calorie deficit. Let's subtract 500 calories from his TDEE:

John's Target Calories = 3,068 calories/day - 500 calories/day = 2,568 calories/day

Step 4: Set Macronutrient Breakdown

Now, it's time for John to choose his preferred macronutrient breakdown. Being a fan of a balanced approach, he selects the Standard breakdown:

40% Carbohydrates, 30% Protein, 30% Fat

Step 5: Calculate Macronutrient Caloric Needs

To find the calorie contribution of each macronutrient, we'll multiply the percentage by the target daily calorie intake:

Carbohydrates: 0.40 × 2,568 calories/day = 1,028 calories/day

Protein: 0.30 × 2,568 calories/day = 770 calories/day

Fat: 0.30 × 2,568 calories/day = 770 calories/day

Step 6: Convert Calories to Grams

Finally, let's convert the calorie contribution of each macronutrient to grams using the calorie-per-gram values:

1g Carbohydrates = 4 calories 1g Protein = 4 calories 1g Fat = 9 calories

Carbohydrates: 1,028 calories/day ÷ 4 calories/gram = 257 grams/day

Protein: 770 calories/day ÷ 4 calories/gram = 193 grams/day

Fat: 770 calories/day ÷ 9 calories/gram = 86 grams/day

Congratulations, John! You've successfully calculated your macronutrient needs. By understanding your BMR, determining your TDEE, setting your target calorie intake, and customizing your macronutrient breakdown, you're well on your way to achieving your health and fitness goals.