To calculate macros for weight loss, follow these key steps:
1. Calculate Your Basal Metabolic Rate (BMR)
BMR is the number of calories your body burns at rest. You can calculate it using formulas such as the Harris-Benedict or Mifflin St. Jeor equations. For example, the Harris-Benedict formula for women is:
BMR=655+(4.35×weight in lbs)+(4.7×height in inches)−(4.7×age)BMR=655+(4.35\times \text{weight in lbs})+(4.7\times \text{height in inches})-(4.7\times \text{age})BMR=655+(4.35×weight in lbs)+(4.7×height in inches)−(4.7×age)
For men, a common formula is:
BMR=66+(6.23×weight in lbs)+(12.7×height in inches)−(6.8×age)BMR=66+(6.23\times \text{weight in lbs})+(12.7\times \text{height in inches})-(6.8\times \text{age})BMR=66+(6.23×weight in lbs)+(12.7×height in inches)−(6.8×age)
Or the Mifflin St. Jeor formula (widely regarded as accurate):
- For men: 10×weight (kg)+6.25×height (cm)−5×age+510\times \text{weight (kg)}+6.25\times \text{height (cm)}-5\times \text{age}+510×weight (kg)+6.25×height (cm)−5×age+5
- For women: 10×weight (kg)+6.25×height (cm)−5×age−16110\times \text{weight (kg)}+6.25\times \text{height (cm)}-5\times \text{age}-16110×weight (kg)+6.25×height (cm)−5×age−161
2. Adjust for Activity Level to Find Total Daily Energy Expenditure
(TDEE)
Multiply your BMR by an activity factor:
- Sedentary (little/no exercise): 1.2
- Light exercise (1-3 days/week): 1.375
- Moderate exercise (3-5 days/week): 1.55
- Heavy exercise (6-7 days/week): 1.725
- Very heavy exercise (twice per day, extra heavy): 1.9
This gives your TDEE, the calories needed to maintain your current weight
3. Create a Calorie Deficit for Weight Loss
To lose weight, reduce your TDEE by about 10-20%, commonly 500 calories per day for roughly 1 pound (0.45 kg) of weight loss per week. Do not go below your BMR to avoid negative health effects
4. Choose Your Macro Ratios
Common macro splits for weight loss are:
- Protein: 30-40%
- Carbohydrates: 30-40%
- Fat: 20-30%
A popular ratio is 40% protein, 30% carbs, 30% fat or 40/40/20 (carbs/protein/fat) depending on preference and goals
5. Convert Calories to Grams of Macros
Use the calorie content per gram:
- Protein = 4 calories/gram
- Carbohydrates = 4 calories/gram
- Fat = 9 calories/gram
Calculate grams by multiplying your daily calorie target by the macro percentage, then dividing by calories per gram. For example, with a 1500 calorie diet and a 40% carb, 30% protein, 30% fat split:
- Carbs: 1500×0.40=6001500\times 0.40=6001500×0.40=600 calories → 600/4=150600/4=150600/4=150 grams
- Protein: 1500×0.30=4501500\times 0.30=4501500×0.30=450 calories → 450/4=112.5450/4=112.5450/4=112.5 grams
- Fat: 1500×0.30=4501500\times 0.30=4501500×0.30=450 calories → 450/9=50450/9=50450/9=50 grams
Summary
- Calculate BMR using your weight, height, age, and gender.
- Multiply BMR by activity factor to get TDEE.
- Subtract calories for a deficit (e.g., 500 calories/day).
- Choose macro percentages based on preference (e.g., 40% protein, 30% carbs, 30% fat).
- Convert calories to grams using 4 cal/g for protein/carbs and 9 cal/g for fat.
- Adjust as needed based on progress.
Online macro calculators can automate this process by inputting your personal data and goals, providing precise macro targets for weight loss
. This method ensures you consume the right balance of macros while maintaining a calorie deficit for effective weight loss.
