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How Many Carbs Should I Eat to Lose Fat and Build Muscle?

To determine how many carbs you should consume each day, you first have to calculate how many calories you need in a day. There are different prediction equations that professionals use, and Nikki recommended the Harris-Benedict equation to determine daily caloric intake. If maths isn't your forte, you can also use an online Harris-Benedict equation calculator.

  • Female: 655.1 + 9.6(weight in kilograms) + 1.9(height in centimeters) - 4.7(age in years) x activity factor
  • Male: 66.5 + 13.8(weight in kilograms) + 5(height in centimeters) - 6.8(age in years) x activity factor

For activity factor, choose one of the following:

  • Sedentary/little to no exercise: 1.2
  • Lightly active (light exercise or sports one to three days a week): 1.375
  • Moderately active (moderate exercise or sports six to seven days a week): 1.55
  • Very active (intense exercise every day or exercising two times a day): 1.725

For example, a 30-year-old woman who is 5'4" (162.5 cm) and weighs 145 pounds (65.9 kg) who is lightly active would use this calculation:

655.1 + 9.6(65.9) + 1.9(162.5) - 4.7(30) x 1.375 = 2,001 calories (this number was rounded)

Because the goal is to lose weight/fat, Nikki said to reduce the original figure by 500 calories. To lose fat and build muscle, this woman should consume 1,501 calories a day. This number will help you determine how many calories you should consume from each macronutrient.

According to Nikki, 50 percent of your macronutrient profile should come from carbohydrates like complex grains and starchy vegetables such as lentils and potatoes. Using the example above, this woman would need 188 grams of carbs a day, or 47 grams per meal: breakfast, lunch, dinner, and a post-workout drink.

To lose fat and build muscle, 25 percent of your daily caloric intake should come from lean protein sources. This is 94 grams of protein a day, or 23.5 grams per meal (breakfast, lunch, dinner, and a post-workout drink). The final 25 percent of your daily caloric intake should come from fats, Nikki said. Based on the example, this woman would need 42 grams of fat a day or 10.5 grams per meal.

Because your macronutrient profile will change based on your goals, Nikki recommends reassessing your goals every couple of months to align your energy needs (aka caloric needs) to your goals. "This takes time as well so I encourage people to find their nearest registered dietitian for help," she said.

Image Source: Getty / Nastasic