How Many Calories Should I Consume to Build Muscle & Burn Fat?

People who embark on a diet and fitness plan usually aim to lose weight as well as get more toned, but can you lose fat and gain muscle at the same time? Here's what you need to know about whether or not it's possible and how many calories you need to build muscle and lose fat.

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People are sometimes under the misconception that fat can be converted into muscle; however, Columbia University explains that fat and muscle are in fact two different types of tissues and that one cannot be converted into the other.

When you eat more calories than your body requires, the extra energy is stored in your body as fat, increasing the size of your existing fat cells, according to Columbia University. When you burn fat, your body uses the energy stored in your fat cells to fuel your activity. This causes your fat cells to shrink in size.

Columbia University notes that your body also has a fixed number of muscle cells, so when you're gaining muscle, or bulking up, your existing muscle cells are actually increasing in size. Similarly, when you lose muscle mass it is due to a shrinkage in the size of your muscle cells, according to a January 2013 study published in the journal ‌Disease Models & Mechanisms‌.

It is therefore important to understand that when you gain or lose muscle or fat, what is actually happening is that your muscle and fat cells are growing or shrinking; at no point do your fat cells convert to muscle cells, since that is physically impossible.

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Columbia University explains that losing fat and gaining muscle involve two different types of metabolic processes: catabolism and anabolism. Losing fat is a catabolic process whereas gaining muscle is an anabolic process. Losing fat and gaining muscle at the same time can be tricky because one requires fewer calories while the other requires more calories. Here's how it works.

Anabolism is a biochemical process where your body synthesizes smaller molecules into more complex ones. Building muscle is an anabolic process since it results in larger, more complex muscle cells. Anabolic processes also result in the capture of energy within your body. Since calories provide energy, anabolic processes like gaining muscle require a consistent calorie intake, notes Columbia University.

While anabolism is one type of metabolic process, catabolism is the other. Catabolism is the process by which your body breaks down larger molecules into smaller ones, releasing energy in the bargain. The catabolic reactions that result in weight loss cause you to lose a combination of fat, water and protein, according to Columbia University. People who go on a diet therefore often lose muscle mass and water weight in addition to fat.

Per the Mayo Clinic, you need to create a calorie deficit, where you burn more calories per day than you consume, in order to lose weight. This is typically achieved by consuming fewer calories and increasing physical activity to burn more calories per day.

However, if you go on a diet and restrict your calorie intake, your body doesn't burn only fat for energy; it also burns carbohydrates and protein. This can inhibit muscle gain, because your body needs the protein for muscle growth and repair; if the protein is burned for energy, then there may not be enough for your muscles, states Columbia University.

So, can you lose fat and gain muscle at the same time? Columbia University says it depends. If you're new to exercise and your body has fat stores it can rely on for energy, then a consistent exercise routine that involves both cardio (catabolic exercise) and resistance training (anabolic exercise) should help you lose fat and gain muscle at the same time.

Things are different if on the other hand your physique is lean and you already have muscle mass. In that case, if you're trying to build more muscle, you would have to increase your protein intake so that you don't lose lean body mass in the process, says Columbia University.

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As you can see, how many calories to build muscle and lose fat isn't a question with a straightforward answer, because there's some balancing involved. You need to ensure that you're getting enough calories, and protein specifically, to help you build muscle, but not so many calories that your body is storing the excess as fat.

So how do you go about calculating how many calories to gain muscle and burn fat? The best thing to do would be to visit a dietitian or nutritionist, since they will be able to help you with a personalized meal plan to help you meet your goals while taking into account your daily routine, likes and dislikes, medical issues and food allergies, if any.

Periodic visits to the dietitian or nutritionist will enable them to track your progress and adjust your meal plan if required, to ensure that you are losing fat and gaining muscle.

In the meantime, here's how you can estimate how many calories to gain muscle and burn fat. The starting point is the number of calories your body requires per day just to survive and perform all its metabolic processes. The American Council of Exercise (ACE) refers to this as the resting metabolic rate.

The ACE lists several factors that can affect your resting metabolic rate, including your age, gender, height, weight, body-fat percentage, body temperature, diet, physical activity level and genetic factors like how fast or slow your metabolism is. For instance, men tend to have more muscle mass and a lower body-fat percentage than women, so their resting metabolic rate tends to be higher.

According to the ACE, one way to calculate your resting metabolic rate in terms of calories required per day is with the Mifflin-St Jeor Equation. The equation has two different versions, one for men and one for women.

This is how you apply the equation for men:
9.99 x weight (kilograms) + 6.25 x height (centimeters) – 4.92 x age (years) + 5

This is how you apply the equation for women:
9.99 x weight (kilograms) + 6.25 x height (centimeters) – 4.92 x age (years) – 161

Once you have calculated your resting metabolic rate, you need to multiply it by a certain number to account for your physical activity, says the ACE. This number varies depending on how active your lifestyle is.

• ‌Sedentary lifestyle‌ (if you have a desk job and get little or no exercise per day): Multiply your resting metabolic rate by 1.2
• ‌Lightly active lifestyle‌ (if you play a sport or get light exercise one to three times a week): Multiply your resting metabolic rate by 1.375
• ‌Moderately active lifestyle‌ (if you play a sport or get moderate exercise three to five times a week): Multiply your resting metabolic rate by 1.55
• ‌Very active lifestyle‌ (if you play a sport or get vigorous exercise six or seven times a week): Multiply your resting metabolic rate by 1.725
• ‌Extremely active lifestyle‌ (if you play a sport or get vigorous exercise every day and are either in physical training or have a physically demanding job): Multiply your resting metabolic rate by 1.9

This equation can help you estimate how many calories you need per day, and you can adjust it as you see changes in your weight, or if you increase or decrease the amount of exercise you get. You can use a calorie tracker to estimate how many calories you currently consume per day, and then you can start regulating your calorie intake accordingly.

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If you currently consume more calories than you require, cutting down your intake by 500 to 1,000 calories per day should help you lose 1 to 2 pounds per week, says the Mayo Clinic. Adding in resistance training to stimulate your muscle cells, eating enough protein and getting adequate sleep should help you build muscle simultaneously, notes Columbia University.

Apart from how many calories to gain muscle and burn fat, it's equally important to pay attention to the type of calories you eat. The Academy of Nutrition and Dietetics lists both protein and carbs as important nutrients while you're trying to build muscle mass.

Protein should make up around 10 to 35 percent of your total calorie consumption per day. The average adult needs around 0.37 grams of protein per pound of body weight per day. However, if you're an athlete, you may need between 1.2 and 2 grams of protein per pound of body weight per day, according to the Academy of Nutrition and Dietetics.

An April 2014 study published in the ‌International Journal of Sport Nutrition and Exercise Metabolism‌ found that a high protein intake was associated with a lower body-fat percentage and higher muscle mass among athletes.

The Academy of Nutrition and Dietetics notes that you also need carbs to fuel your workouts. When you eat carbs, they are partially converted to glycogen and stored in your muscles, providing fuel for your muscles when you exercise.

Around half the calories you eat per day should be from carbs, says the Academy of Nutrition and Dietetics; however, you need to make it a point to opt for high-quality carbs like whole-grain breads and cereals, low-fat dairy products, fruits and vegetables, instead of unhealthy carbs like cakes, pizzas and bagels.

When it comes to fat, the Academy of Nutrition and Dietetics recommends sticking to unsaturated fats, like nuts, fatty fish, olive oil and canola oil. Fat has more than double the number of calories as carbs or protein, so it's important to limit your portion sizes of fatty foods.

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