Low-Carb Diets Hinder Muscle Growth & Performance, According To A New Science Review

Carbs have long been demonized in the well-being world, and as of 2022, 14% of Americans were following a ketogenic or low-carb diet.

A recent review study published in Current Opinion in Clinical Nutrition and Metabolic Care analyzed research on ketogenic diets, low-carb diets, weight loss, insulin regulation, muscle formation, endurance exercise, and more. It's a comprehensive summary of what we know about the intersection of low-carb diets and muscle gains.

The review suggests that limiting carbs can increase protein oxidation, thereby limiting the availability of essential amino acids—which are necessary to stimulate optimal muscle protein synthesis and promote recovery. 

Authors note that keeping up with a low-carb diet (eating fewer than 130 grams of carbs1 or less than 26% of total calories from carbs per day) for eight to 12 weeks can further limit essential processes that impact the growth of muscle cells—specifically in the case of anaerobic exercises like weightlifting.

In other words, severe carb restriction can be detrimental for those regularly performing high-intensity exercise—especially when continued beyond a week or two. 

Rather than severely restricting one macronutrient, this review suggests we might consider taking a more food-inclusive approach to building strength. Some carbohydrates can play a key role in muscle mass and overall health.

While protein isn't the only macronutrient you should focus on for muscle gain, it's still high on the list. The Recommended Dietary Allowance for sedentary adults is 0.8 gram per kilogram of body weight per day—but active folks should be getting much more. Instead, shoot for 1.2 to 2.0 grams of protein per kilogram of body weight, prioritizing protein high in leucine—an amino acid essential for muscle building.

To keep your energy up, pair your protein with complex carbohydrates. "Complex carbs in fruits, vegetables, whole grains, and legumes give you the energy required for strenuous exercise, while protein helps repair and build muscle," certified holistic nutritionist Adam Meyer previously wrote on mindbodygreen. Combining the two macronutrients is also beneficial for blood sugar stabilization3.

If you're looking to build muscle, you'll want to start strength training, focusing on increasing the amount of weight that you lift over time to continue to put sufficient tension on your muscles.

GET STARTED: The Only Guide to Strength Training You'll Ever Need (With 33 Exercises)