Protein, alongside carbohydrate and fat, is one of the three macronutrients (as opposed to vitamins and minerals, which are micronutrients). It's present in every cell in the body, and essential for cellular growth and repair – particularly in muscle tissue. Protein matters for everyone, not just those training or building muscle, and it also plays a role in providing sustained energy throughout the day.
How Much Protein Do You Actually Need?
UK guidelines recommend around 45g of protein a day for adult women and 56g for adult men – roughly two to three portions daily, where one portion is approximately 100g of lean meat, two eggs, or three tablespoons of nuts, seeds or beans. Anyone training at high intensity or actively working to build muscle will typically need more than this baseline.
Sources of Protein
Meat is the source most people think of first, and for good reason – red meat, poultry and fish are all strong protein sources. That said, it's worth being mindful of saturated fat in fattier, processed meats. Sticking to lean cuts like chicken or turkey breast and fish, and keeping red meat to lean options rather than sausages, bacon or burgers, is a sensible general approach.
For vegetarians, eggs are a strong protein source, alongside low-fat dairy like plain yoghurt and cottage cheese. If eggs cause you any digestive discomfort, it's worth being aware that egg intolerance is a genuine, if less commonly discussed, possibility worth ruling out.
Protein doesn't have to come from animal products at all. Vegans, those on a plant-based diet, or anyone reducing animal food intake can meet their full protein needs through plants, with a little more planning. Strong plant-based sources include nuts, seeds, peas, beans of all kinds, chickpeas, lentils, meat alternatives, and soya-based foods like tofu. Nut and soya milks, along with nut butters, are also useful protein sources. If peas specifically don't agree with you, it's worth knowing that pea allergies do exist and are worth investigating if you notice a pattern.
A daily smoothie with protein powder, your milk of choice and some fruit is a straightforward way to top up protein intake, particularly around exercise or training. Most protein powders use whey (typically from cow's milk), though a wide range of plant-based alternatives are now widely available.
Complete and Incomplete Protein
Meeting your protein needs through plants alone is entirely achievable, but variety matters. Protein is made up of chains of amino acids – the "building blocks" of protein – of which there are around 20 types. Some are classed as essential amino acids, meaning the body can't produce them and they must come from diet; the rest are non-essential, since the body can make them itself.
Animal-based protein sources typically contain all the essential amino acids, making them "complete" proteins. Plant-based sources tend to vary in which essential amino acids they contain, making most of them individually "incomplete" – which is why variety matters if you're relying mainly or entirely on plant protein. Mixing different nuts, seeds, beans and legumes across the week helps ensure you're covering the full range.
If you're feeling persistently tired or low on energy, it's worth taking an honest look at whether you're getting enough protein day to day – and if digestive symptoms are part of the picture too, a food intolerance test can help rule out whether a specific protein source is contributing.
