Most adults need around 0.8–1g of protein per kg of body weight per day. Although people who are unwell, recovering from an operation, or who have a bad wound may need closer to 1.5g per kg.
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On average, the UK’s Department of Health recommends that women should eat 45g of protein and men should eat 55.5g of protein each day.3
It’s worth noting that this doesn’t take individual differences into account, so it’s important to consider your weight in kilograms, your exercise levels and whether you’re recovering from an illness or surgery.3 For example, if you’re wondering how much protein is needed to build muscle, people who do regular, intensive exercise, including athletes, need to aim for more protein - around 1.2–2g per kg of body weight per day.4,5
This is because, a few studies point out prolonged endurance training sessions can damage and disrupt the muscle being used, meaning that the body needs more protein to be able to repair the muscle and contribute to gains in muscle mass and strength.6,7
However, whatever your protein requirements, it should be entirely possible to get all the eight essential amino acids you need by eating a wide range of protein-rich food (your body can only make some of these so you must get the complete range from your diet).8
Though of course, if your protein requirements are on the higher end, you may find it easier to reach your protein requirements by using supplements with guidance from a healthcare professional.