Why is protein important?
Protein is one of the three essential macronutrients, alongside fats and carbohydrates, that play a crucial role in our diet. It serves as the building block for our hair, skin, bones, and muscles. Moreover, proteins are vital for producing enzymes, hormones, and neurotransmitters, all of which facilitate important communication within the body.
Proteins consist of long chains of amino acids, which the body utilizes for muscle growth and repair. Out of the 20 amino acids, nine are classified as essential, meaning our bodies cannot synthesize them; we must obtain them from our diet. High-quality protein sources, such as meat, fish, and certain plant-based options like soy, quinoa, buckwheat, and Quorn, contain all essential amino acids.
Protein is crucial for maintaining muscle mass throughout life, which is integral to metabolic health, physical strength, mobility, and our overall independence. Notably, muscle tissue is the largest contributor to our resting energy expenditure, continuing to burn calories even when we are at rest.
Explore our comprehensive range of health benefit guides, including everything you need to know about protein, the 10 best sources of protein, and our collection of high-protein recipes, including options for vegetarians and vegans.
Who needs protein more?
Everyone requires protein in their diet. However, individuals engaged in endurance sports or weight training may benefit from increasing their protein intake as part of their training regimen.
Research indicates that as we age, our protein requirements may rise. This increase is partly due to the fact that dietary protein helps mitigate muscle loss associated with decreased activity levels and aging. Inadequate protein consumption can lead to a condition called sarcopenia, which results in increased muscle loss and can lead to physical frailty and a higher risk of falls.
What happens when I eat protein?
Upon consuming protein, the digestion process begins in the stomach and proceeds to the duodenum, the first part of the small intestine.
The small intestine absorbs approximately 40-50% of the amino acids present; these can be utilized for energy (1 gram of protein yields 4 kcal) and local protein synthesis.
The remaining amino acids are transported into the hepatic portal vein and absorbed by the liver, with an estimated 10-20% of ingested protein ultimately converted into skeletal muscle.
How does protein influence muscle health?
Protein is necessary for muscle development as it provides the essential building blocks of muscle tissue. A sufficient intake not only aids in muscle maintenance but also fosters growth and repair, particularly post-resistance exercise. Muscle growth is maximized when regular resistance training is paired with adequate dietary protein consumption.
The effectiveness of muscle synthesis is influenced by both the amount and quality (amino acid composition) of protein consumed. Additional factors, including age and overall health, along with gut bacteria, may also affect how efficiently your body uses protein.
Are some protein foods better at building muscle than others?
Not all proteins are created equal; lower-quality proteins, like wheat protein, may lack one or more of the nine essential amino acids, which diminishes their ability to stimulate muscle protein synthesis relative to complete proteins like whey. High-quality protein sources provide all nine essential amino acids, which support muscle growth.
Leucine is regarded as the primary amino acid necessary to initiate muscle synthesis. It can be found in animal products such as meat, fish, dairy, and eggs, as well as in plant sources like soy and nuts. High-quality plant-based protein powders labeled as ‘concentrates’ or ‘isolates’ are also excellent options.
What happens when we have too little protein?
Insufficient protein intake can lead to a range of health issues: muscle loss may result in decreased strength, impaired balance, and mobility challenges, especially in older adults. A lack of protein may also disrupt appetite regulation, potentially leading to weight gain and increased body fat.
Initial signs of inadequate protein consumption may include deteriorating hair, nails, and skin conditions. Other symptoms might involve prolonged healing times for wounds, increased susceptibility to colds and infections, potential anemia, muscle weakness, and swelling in the legs, feet, and hands. Additionally, fatigue and noticeable changes in body composition and posture may occur.
How much protein do I need to build muscle?
In the UK, the Reference Nutrient Intake (RNI) is set at 0.75g of protein per kg of body weight, which is the minimum required to prevent loss of lean body mass, based on an average sedentary adult. These figures are often misinterpreted as optimal recommendations, so if you’re aiming to build muscle, this amount is typically insufficient.
Determining the ideal protein intake can be complex, as requirements differ from person to person. Factors such as age, weight, height, gender, overall health, physical activity level, and the intensity of that activity all play a crucial role. Additionally, body composition and existing muscle mass influence protein needs.
A general guideline for daily protein intake is approximately 1.2g per kg of body weight to maintain muscle. This may increase to 1.2-1.6g/kg of body weight for those looking to gain lean mass or for women in midlife during this stage.
A weightlifter or strength athlete aiming to add muscle mass—who will naturally utilize their muscles more—will generally require between 1.4-2g/kg of body weight per day. Endurance athletes are recommended to consume between 1.2-2.0g/kg of body weight.
For a more tailored approach, calculate your body fat percentage in kg and subtract that from your total weight to determine your lean body mass. If your goal is muscle gain, you may aim for about 2g/kg of lean body mass.
How much protein should I eat after exercising?
Several studies suggest that consuming 0.2-0.5g of protein per kg of body weight post-exercise can stimulate muscle synthesis. Depending on your weight and the intensity of your workout, this typically translates to a meal or snack providing 10-30g of protein.
The longer and more intense your workout, the greater your protein requirements, as muscle breakdown and rebuilding are elevated for 24 hours following exercise. Consuming protein within 30 minutes after working out is beneficial since muscles are especially responsive during this window.
What are the dangers of too much protein?
Consistently consuming excessive amounts of protein has been linked to bone loss and kidney damage, although in otherwise healthy individuals, evidence for these effects is limited. It appears that high-protein diets are primarily a concern for those with pre-existing conditions or kidney issues. For healthy adults, increased protein intake may actually help avert muscle loss and bolster bone health.
In general, for most healthy adults, following a high-protein diet for a limited time (a few months) poses minimal risks. However, the long-term consequences of high-protein diets combined with low carbohydrate intake are still being investigated, and results may vary based on age and genetics.
In conclusion, for most healthy individuals, a protein intake of up to 2g/kg of total body weight daily is generally considered safe.
How can I maintain and build muscle mass?
If your goal is to sustain or increase your muscle mass, consider implementing these practical strategies:
Please consult your GP or a registered dietitian before making any significant dietary changes to ensure your approach is safe and appropriate.
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