How much Protein do I need? 

IMPORTANCE OF PROTEIN IN THE DIET

Proteins are a part of every cell and tissue, including our muscle. Our bodies are constantly recycling proteins, by breaking down older proteins and replacing them with new ones. The proteins that we consume through our diet plays a key role in ensuring those looking to build muscle, lose fat or improve performance have their needs met. These include; 

• Maintaining and growing muscle tissue 

• Providing the building blocks for connective tissues 

• Supporting the immune system and promoting muscle mass recovery after training ¹. 

PROTEIN REQUIREMENTS 

The Daily Recommended Allowance (RDA) for protein is currently set at 0.8g per kilogram of body weight for the average person. Nevertheless, it is increasingly acknowledged that athletes and individuals that regularly engage in physical activity have higher protein requirements to support metabolic adaptation and muscle repair and remodelling. The International Society of Sports Nutrition currently recommends a protein intake of 1.4-2.0 g/kg of body weight for individuals that resistance train⁶.  

Based on this, an 70kg individual who resistance or strength trains 3-5 time per week would benefit from a protein intake ranging from 120-140g per day. Apart from the type of training performed, protein requirements are also influenced by our energy availability, with different amounts of protein being required when we are aiming to maximise muscle growth, compared to a period of weight loss.  

HOW DOES PROTEIN BUILD MUSCLE?

The process through which new muscle proteins are formed is called muscle protein synthesis (MPS). This process is increased by resistance training for up to 24hr period during which there is also an increase in sensitivity to the intake of dietary protein, with its consumption during this period further increasing MPS ³. This is highly important as MPS must exceed muscle protein breakdown (MPB) for muscle hypertrophy (growth) to occur.  Numerous scientific studies all show that protein supplementation during a multi-week resistance programme leads to increased muscle gain ^4,5, supporting the importance of sufficient protein consumption for muscle growth.  

HOW MUCH PROTEIN SHOULD I CONSUME IF I WANT TO BUILD MUSCLE?

Recent meta-analysis showed that 1.5 g/kg of body weight per day may be the most appropriate amount of total protein intake for increasing muscle strength along with resistance training ⁷. A 70kg individual, achieving a daily protein intake of 110-140g would optimally support muscle strength and muscle gain while being on a caloric surplus, an important element for building muscle mass. Nevertheless, protein requirements can further increase during a period of caloric deficit.  

HOW MUCH PROTEIN SHOULD I EAT WHEN LOSING FAT?

Aside from achieving a caloric deficit, which is the key driver for fat loss, consuming an appropriate daily protein intake during a period of fat loss represents a key fact due to its beneficial effects on maintaining muscle mass. Protein requirements increase during periods of fat loss with several studies showing that consuming a daily protein intake of 2.0-2.4 g/kg body weight during periods of calorie restriction (which is required for fat loss) results in a lower muscle mass being lost ^8,9,10.   

Consuming a high-protein intake can also help fat loss due to its high thermogenic effect (increase in energy expenditure that happens after eating). Around 20-30% of the calories consumed through protein are used by our bodies for metabolism and/or storage. Last, high-protein diets also prevent a decline in resting energy expenditure, a key factor that influences our total energy expenditure and long-term fat loss and weight maintenance.  

Based on scientific studies, a 75kg individual who is looking to maximise the retention of their muscle during a period of fat loss should consume between 150-180g of protein per day. 

HOW MANY SERVINGS OF PROTEIN DO I NEED PER DAY?

The number of high protein meals throughout the day and the protein content of each feed are also important factors. It is recommended that 4-5 meals and or/snacks rich in protein should be consumed throughout the day¹¹. Each protein feeding should include between 20-40g protein, with 40g being optimal following a full-body resistance training session. Another protein feed can be provided before sleep to stimulate the production of muscle proteins over-night and increase muscle mass and strength gains ¹². 

HOW MUCH PROTEIN CAN BE USED BY THE BODY IN A SINLE SERVING?

Although the research previously indicated that 20-25g of protein is sufficient for maximising post-exercise MPS, a recent study showed that consuming 100g of protein in one meal can further enhance the anabolic response as compared to only consuming 25g of protein ^14.  This provides initial evidence to support the integration of higher protein meals (>40g) for supporting muscle mass gain, particularly during busy periods of time when having frequent meals (every 3-4 hours) is not possible. The findings of this study also further highlight that the total amount of protein consumed in one day represents the most important factor for supporting muscle mass gain, followed next by the total number of high protein meals and their timing. 

PROTEIN SOURCES

High-quality protein sources with a complete amino acid profile such as milk, eggs, fish and lean meats should be prioritised during periods of both muscle mass gain and fat loss. These animal sources of protein are also rich in leucine, an amino acid that plays a key role in the synthesis of muscle proteins. On top of this, high-quality supplements such as protein powders (whey and casein powders) and protein bars can be consumed throughout the day to stimulate MPS and to help you reach an optimal daily protein intake.  

Plant-based alternatives

The role of plant-based protein sources for supporting muscle mass gain is also becoming increasingly acknowledged ¹³. Plant-based source of protein include beans, lentils, chickpeas and soy, and these can be effectively incorporated as part of a muscle-building diet. Special consideration should be provided when only plant-based protein sources are consumed during a meal, with a combination of multiple protein sources being recommended to enhance the amino acid profile and the leucine content of the meal. 

WHY IS LEUCINE IMPORTANT?

Leucine is a branched-chain amino acid that plays a unique role in stimulating the muscle protein synthesis response. Currently it is recommended that 2-3g of leucine should be incorporated into a high protein-meal to maximally stimulate the MPS response ⁶ . Although leucine can individually stimulate the MPS response, its consumption alongside other essential amino acids is preferred to maximally stimulate the anabolic response after a meal. Leucine rich sources include whey and casein protein, chicken, beef, eggs and tofu. 

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