Protein is often referred to as the building block of life – and rightly so. This vital macronutrient plays a central role in nearly every process within the body, from building muscle to supporting the immune system. As nutritional science continues to evolve, we're learning even more about how protein can significantly improve overall health and wellbeing.
The Essential Role of Protein
At its most basic level, protein is made up of amino acids – organic compounds that underpin countless bodily functions. While our bodies can produce some amino acids, others (known as essential amino acids) must come from our diet. That’s why consuming sufficient, high-quality protein is crucial for maintaining good health.
Protein isn’t just important for athletes or bodybuilders – it’s a necessity for everyone, regardless of age, fitness level or health goals. From healing wounds and producing enzymes to maintaining muscle mass and regulating hormones, protein is hard at work behind the scenes, supporting your body in ways you might not even realise.
Weight Management and Metabolism
One of the most widely recognised benefits of protein is its role in supporting healthy weight management. Protein-rich foods help you feel fuller for longer compared to carbohydrates or fats, which can lead to a natural reduction in calorie intake. Studies, including those published in the British Journal of Nutrition, have shown that a higher protein intake is linked with reduced hunger and increased feelings of satiety.
Protein also has a higher thermic effect than other macronutrients – meaning your body uses more energy to digest it. While this boost in metabolism may be modest, it can still support weight control when combined with a balanced diet and regular physical activity.
Muscle Health and Preservation
Protein is perhaps best known for its critical role in building and maintaining muscle. But it’s not just about bulking up – protein is essential for preserving existing muscle mass, especially as we age.
From around the age of 30, we begin to lose muscle mass at a rate of roughly 3–8% per decade – a process called sarcopenia, which accelerates after the age of 60. This can lead to reduced strength, frailty and even a loss of independence. A diet rich in protein, along with regular resistance training, can help slow this decline, supporting healthier ageing and better mobility.
Immune Function and Recovery
Your immune system also depends on protein. Antibodies – the proteins that help your body fight off infections – are just one example. Many immune cells also require protein for their formation and function. During periods of illness or injury, the body’s protein requirements increase to support tissue repair and immune responses.
Research from University College London indicates that even mild protein deficiency can weaken the immune system, making recovery slower and increasing vulnerability to infection. For those healing from surgery, illness or injury, ensuring sufficient protein intake is particularly important.
How Much Protein Do You Need?
In the UK, the Reference Nutrient Intake (RNI) for adults is 0.75g of protein per kilogram of body weight daily. However, many experts now recommend higher intakes for certain groups, including older adults, those looking to lose weight, or people with active lifestyles.
General guidelines based on current research suggest:
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Sedentary adults: 1.0–1.2g per kg of body weight
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Active adults: 1.4–2.0g per kg of body weight
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Older adults (65+): 1.2–1.5g per kg of body weight
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Athletes and heavy exercisers: Up to 2.2g per kg of body weight
For example, a moderately active person weighing 70kg might aim for between 98g and 140g of protein per day.
High-Quality Protein Sources
It’s not just about how much protein you consume – quality matters too. Complete proteins, which provide all nine essential amino acids, are especially beneficial. These are found in:
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Animal sources: Lean meats, poultry, fish, eggs, dairy
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Plant sources: Soya, quinoa, buckwheat, hemp seeds
Other excellent plant-based protein sources include:
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Legumes: Lentils, beans, chickpeas
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Nuts and seeds
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Whole grains
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Mycoprotein (e.g., Quorn)
For those following a vegetarian or vegan diet, combining different plant proteins across the day ensures you’re getting all the essential amino acids your body needs.
Timing and Distribution
Recent studies suggest that when you eat protein can be just as important as how much you eat. Rather than consuming most of your daily protein in one meal – often dinner – try to spread it evenly throughout the day. Aim for 20–30g of protein at each main meal to maximise muscle protein synthesis and maintain steady energy levels and satiety.
Final Thoughts
Protein is an incredibly powerful macronutrient, with far-reaching effects on everything from body composition and metabolism to immune function and healthy ageing. By prioritising both the quality and distribution of your protein intake, you can unlock its full potential to support your health and wellbeing goals.
As always, nutritional needs vary from person to person. Individuals with kidney issues or certain medical conditions should consult their GP or a dietitian before significantly increasing their protein intake. But for most healthy adults, making protein a central part of your diet can be a real game-changer for your vitality and long-term health.
