The scale can tell you whether you've lost, gained or maintained weight, but it doesn't tell the full story. While bodyweight refers to total mass, body composition refers to the muscle, bone, water, and fat that make up total mass. Understanding these ratios is the first step in healthy eating and improving your body composition using calories and macronutrients.
What Are Calories?
A calorie is a unit of energy sourced from food, and every cell in your body needs calories to function properly. The amount of calories your body needs each day to maintain itself is called your basal metabolic rate.
Weight loss happens when you consistently eat less than your BMR plus whatever calories you use from expending energy through chores, walking around, or intentional exercise. Weight gain happens when you consistently eat more.
What Are Macros?
Good nutrition comes from a macro-balanced diet. Macronutrients or macros make up your food composition and perform different functions for your body. There are three macronutrients, each measured by calories:
- Protein (4 calories per gram): Essential for building and repairing tissues and maintaining lean body mass
- Carbohydrates (4 calories per gram): Simple and complex carbs break down into glucose and are an energy source for your body
- Fats (9 calories per gram): Healthy fats can help your body store energy and promote overall hormonal and cellular health
Macronutrients are a big factor in determining your overall body composition. For instance, a diet composed of 90% carbohydrates will have much different health and composition results compared to a macro-balanced diet.
How to Calculate Macros
Tracking calories and macros can be broken down into a few easy steps.
1. Determine Calorie Needs
BMR calculators can help you determine your caloric needs and adjust this number based on your activity level, age, weight, and other factors.
For example, a 25-year-old female weighing 145 pounds might need 1,684 calories per day if they get little to no exercise, but the same person exercising four times per week may need 2,176 calories.
Consuming 500 to 1,000 calories fewer than BMR can support weight loss, and consuming 500 to 1,000 more than BMR can help with weight gain.
2. Calculate Macronutrients
Macronutrient calculations are based on BMR. Healthy macronutrient distributions generally fall within these ranges:
- Protein: 10% to 35% of calories
- Carbohydrates: 45% to 65% of calories
- Fats: 20% to 35% of calories
For an individual with a 1,700-calorie BMR and a 20% protein, 60% carbohydrates, and 20% fats ratio, macronutrients would look like:
- Protein: 1,700 x 20% = 340 calories / 4 = 85 grams
- Carbohydrates: 1,700 x 60% = 1,020 / 4 = 255 grams
- Fats: 1,700 x 20% = 340 / 9 = 38 grams
Adjusting ratios can support different goals. For example, higher fat and protein ratios may help reduce body fat percentage, but higher carbohydrates can help with performance and recovery in workouts.