Can You Build Muscle in a Calorie Deficit?

If your health goals include building muscle while losing fat and excess weight, you may wonder if you can build muscle while in a calorie deficit (when you eat fewer calories than your body uses). You can, but there are some qualifications.

Building muscle while in a calorie deficit depends on getting enough protein and using resistance training. This article looks at how you can build muscle while working on weight loss.

How a Calorie Deficit Works

A calorie is a measure of energy. Your body uses energy even when you're sitting or sleeping. If you are moving or exercising, you use more calories. When you expend more calories than you take in, you are at a calorie deficit, and that can result in losing weight.

You can safely lose weight as long as you're still getting the nutrients you need. However, weight loss can include losing muscle mass as well as fat.

Is It Possible to Gain Muscle When In a Calorie Deficit?

If you want to lose weight and still build muscle, it's possible as long as you find a balance in your routine, which includes:

• Eating enough protein: The body uses protein to build muscle, so you need to eat enough for your body to convert to muscle tissue.
• Not overdoing the calorie deficit: Slower weight loss reduces the lean mass you lose, including muscles and soft tissue.
• Exercise using resistance training: Resistance exercises use opposing force to muscle contraction to stimulate building muscle. Examples of resistance exercise include lifting weights, using exercise bands, body weight exercises, and exercise equipment focused on specific muscle groups.
  

Protein and Resistance Training for Building Muscle

Current guidelines for muscle mass building recommend a protein intake between 1.2 to 2.0 grams (g) per kilogram (kg) of body weight per day (g/kg/day), as recommended by the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine. This is equal to 0.54 to 0.9 g per pound per day.

That amount varies according to age, weight, general health, and activity level. If you're calculating calories, there are 4 calories per gram of protein.

Effective resistance training stimulates the creation of muscle fibers. First, the exercise breaks down muscle protein, which is called "catabolism." That causes the tissue to rebuild, which results in an increase in muscle mass called "anabolism." The gain is greater than the loss.

If you don't consume enough dietary protein, your body doesn't have the components it needs to build more muscle.

Any exercise that incorporates working against the force of gravity is resistance training—you want to make your muscles contract. The type and amount of resistance training need to be challenging enough to break down muscle tissue, which stimulates it to rebuild.

When you do resistance training, as with any exercise, it's important to use proper techniques to avoid injury. 

Losing Fat While Maintaining Muscle

Losing weight by dieting without exercising will result in losing muscle as well as fat. Eating protein helps preserve lean muscle mass, and as long as you have a calorie deficit, you'll still be on track to lose weight primarily through fat loss.

If you aim to lose fat and maintain muscle rather than increase muscle mass, you can adjust the amount and type of exercise you do. Resistance exercise is still key to maintaining muscle mass while dieting, and endurance exercise can also help.

Setting the Right Calorie Deficit

Drastic dieting can lead to unhealthy muscle loss and other harmful health effects, including dehydration, loss of bone density, malnutrition, and hormonal and immune system imbalances.

To set an effective calorie deficit goal, you can either reduce your calorie intake by eating less food or increase your calorie expenditure through activity.

One older rule of thumb is that people need to burn 3,500 calories more than they take in to lose 1 pound of fat. That equates to cutting 500 calories a day from your food to lose 1 pound a week. You could also cut your calorie intake by 250 calories and increase exercise to burn the rest of the calories.

This rule of thumb is disputed and depends on many other factors. How many calories a day should you aim for? It depends on age, fitness, activity level, and other factors. A good quality online calculator can help you determine caloric intake for weight loss.

A diet of about 1,000 to 1,500 calories a day is considered a low-calorie diet. Anything under 1,000 calories is a very low-calorie diet and should also be done only under professional supervision. To preserve muscle mass, aim for about 10% to 35% of your diet to be protein.

For comparison, a maintenance diet typically ranges from about 1,600 to 2,400 calories a day for an adult female and 2,200 to 3,200 calories a day for an adult male.

Who Can Help in Setting Your Goals?

Losing weight and building muscle at the same time is possible, but to do it in a healthy way, you may need the advice of a professional. Consider consulting a registered dietitian or a certified personal trainer to help you set effective and reasonable goals.

If you have not been active, have chronic health concerns, or have obesity, talk to a healthcare provider before you begin a program of diet and exercise.

A Word From Verywell

With the amount of contradicting information online, figuring out where to start your fitness journey can be challenging. Working with registered dietitians and certified personal trainers can help clear up misinformation and gear your nutrition and training to your needs.

— JONATHAN PURTELL, RD, MEDICAL EXPERT BOARD

Summary

It is possible to build muscle mass while at a calorie deficit, but it takes finding a balance between cutting calories, eating sufficient protein, and using resistance training to stimulate the creation of muscle tissue. Slow and steady weight loss while building muscle is the healthiest approach, with protein forming about one-third of your diet.