Getting Your Leucine: What It Does and Foods To Eat

You probably know you need protein in your diet. But you may not realize that not all protein is the same. So when you’re scrutinizing what you eat, it’s important to consider what’s in your preferred protein sources.

Leucine is a component of protein and can make a big difference in your well-being. But what does leucine do? And how can you make sure you’re getting it on your plate? Family medicine physician Manisha Chand, MD, shares advice.

What is leucine?

Leucine is one of 20 amino acids — the building blocks that make up protein.

Nine of those amino acids — including leucine — are considered essential, meaning you only get them through food. The other 11 are called nonessential. Your body makes those ones on its own.

Breaking it down even further, leucine is one of three branched-chain amino acids (BCAAs). They’re called that because their chemical structure looks ... well, like a branch. The other BCAAs are isoleucine and valine.

Benefits of leucine

If you know one thing about protein, it’s probably this: It’s needed for muscle growth. And BCAAs like leucine are the reason it gets that reputation.

“Branched-chain amino acids are the ones that help to build and repair muscle,” Dr. Chand explains. “They’re essential for muscle growth and function and are used as fuel.”

That means leucine is important for everyone. We all need a healthy lean muscle mass to help our bodies stay strong. Leucine can help to:

• Build and maintain muscle mass: When you shed pounds, you can lose muscle tone if you don’t get enough leucine and other BCAAs. “When we lose weight, what we really want to do is reduce fat and build and retain muscle,” Dr. Chand points out. “Leucine can help to maintain and grow lean muscle mass, which in turn helps you lose fat.”
• Counteract age-related muscle loss: As we age, we tend to lose muscle mass. Leucine can help with that. “Your body’s ability to synthesize protein effectively can decline as you age. So, people in their 60s and beyond can benefit from more dietary protein and leucine specifically to boost their muscle mass,” Dr. Chand suggests.
• Recover from workouts: Exercise enthusiasts benefit from leucine because it helps to repair muscle after a sweat session. That means fewer aches and pains and more energy to power your next workout.
• Improve metabolism: Leucine can help your body burn fat more efficiently. “Muscle is more metabolically active,” Dr. Chand explains. “When you have a higher muscle mass, you burn more calories at rest.”

Foods high in leucine

Leucine is found in protein-rich foods, both from plant-based sources and animal products.

Check out the leucine content of some common protein sources:

“You’ll get leucine from just about any protein you choose, the exception being highly processed and packaged foods. They can lose leucine in manufacturing,” Dr. Chand shares.

So, if you’re looking to properly power up with protein, stick to more natural forms of it. Think roasted chicken breast, not nuggets. Ground turkey, not frozen turkey burgers.

What about leucine supplements?

If you’re concerned about your protein intake, you might be considering leucine powders or pills. After all, what could be more convenient?

Leucine and BCAA supplements might be worthwhile for some people, Dr. Chand agrees. But it’s always better to get your nutrition from foods when you can.

“I recommend thinking about supplementation not as replacement, but as a way to get some added amino acids for people who aren’t getting enough protein through their diets,” she advises. “Most of the patients I see don’t get enough protein in their day. So, carefully looking at your diet is step one. And supplements can help if that’s still not enough.”

Before starting supplements, though, it’s always best to talk with a healthcare provider, like a primary care physician or a registered dietitian. They can help you understand if that’s a healthy choice for you and determine a proper dosage.

“Your provider may want to run some bloodwork before recommending BCAA supplements because they might not be right for you if you have conditions like kidney disease or other concerns,” Dr. Chand points out.

How much leucine do you need?

It’s recommended that adults get 42 milligrams (mg) of leucine for every 2.2 pounds of body weight. To calculate your needs, take your body weight and divide it by 2.2. Then, multiply that number by 42.

So, for example, if you weigh 150 pounds, you should look to get 2,864 mg of leucine per day.

(Note: This number may be higher in older adults, athletes and very active people.)

Bottom line

Protein is an important part of a healthy diet. And leucine is one of the components of protein that helps keep your body healthy and strong.

If you’re concerned about your protein intake or are considering supplements, talk with a healthcare provider.