To build muscles and to stay in peak fitness, here's how much protein you need in your daily diet

Certain amino acids, such as valine, leucine, and isoleucine (known as branched-chain amino acids), are particularly crucial for muscle maintenance and growth, says dietician Shruti Goel. Upon protein consumption, these amino acids are broken down and utilised to build and repair muscle fibres that may have incurred damage during physical activity. This process, known as muscle protein synthesis (MPS), is essential for muscle recovery and growth.

Conversely, insufficient protein intake can lead to a negative protein balance, where the body breaks down muscle tissue to acquire the necessary amino acids for other bodily functions. Over time, this can result in decreased muscle mass and strength, says Goel.

How much protein do you need?

The Recommended Dietary Allowance (RDA) for protein is 0.8 gm per kilogram of body weight for minimally active adults, aiming to prevent deficiency. However, if your focus is to build muscles, research indicates that higher protein intakes offer benefits.

According to the 2020-2025 Dietary Guidelines for Americans, most healthy adults should aim to consume between 10-35 percent of their daily calories from protein. For example, if you consume 2,000 calories per day, this translates to approximately 50-175 grams of protein.

Several studies have shed light on the optimal protein intake for muscle growth:

A 2020 meta-analysis published in Nutrition Reviews found that protein intakes ranging from 0.5 to 3.5 gm per kilogram of body weight can support increases in lean body mass.

Another meta-analysis from 2022 in Sports Medicine concluded that around 1.5 gm per kilogram of body weight daily, coupled with resistance training, is optimal for enhancing muscle strength.

A 2022 systematic review and meta-analysis in the Journal of Cachexia, Sarcopenia, and Muscle suggested that a protein intake of 1.6 gm per kilogram of body weight per day or higher leads to slight increases in lean body mass, particularly in young, resistance-trained individuals.

Though precise figures may vary, aiming for 1.2 to 1.6 gm of protein per kilogram of body weight appears effective for muscle growth. For instance, a 81.8 kg male might target between 98 and 131 grams of protein daily.

Best protein sources

To meet your daily protein requirements, you can select from a variety of animal and plant-based protein sources. Says Goel, "Animal-based proteins, such as lean meats, poultry, eggs, fish, seafood, and dairy products, are rich in essential amino acids and easily digestible. Additionally, whey protein powders offer a convenient option for supplementation."

She adds, "Plant-based proteins, including beans, peas, nuts, lentils, seeds, soy products, and plant-based protein powders, are also valuable sources. While some plant-based proteins may have varying amino acid profiles and lower bioavailability, they can still contribute to muscle growth when combined effectively."

Goel suggests that if you follow a plant-based diet, combining complementary plant proteins can ensure you receive all essential amino acids. "Examples include combinations like rice and beans, hummus and pita bread, or peanut butter on whole wheat bread. Soy stands out as a complete plant-based protein with a favorable amino acid profile and high bioavailability," Goel says.