Adverts for protein powder are everywhere right now. For the uninitiated, many feature a ripped guy flexing his Stanley cup like a dumbbell. But getting enough protein isn't just for those wanting to build muscle with weights. It's crucial for anyone, as it keeps every part of your body ticking like a well-oiled machine, from your bones and immune system to your fingernails.
Your body contains more than 10,000 different proteins. These proteins are made up of molecules called amino acids. “Your body needs a total of 20 different amino acids to function correctly,” says nutritionist Riya Lakhani-Kanji. “But your body isn't capable of producing all of them on its own. It can only make 11 of these essential amino acids. To meet all your body's needs, you need to obtain the remaining nine amino acids through your diet.”
All of these amino acids are vital for your body. “Amino acids are the building blocks of protein, essential for muscle growth, repair and maintenance," says nutritionist Milena Kaler.
“They can also be used as an energy source during prolonged exercise and are involved in the production and function of immune cells," she continues. "Certain amino acids are precursors to neurotransmitters and various hormones. For example, tyrosine is needed for the production of thyroid hormones. Amino acids are also crucial for collagen synthesis, which provides structure to skin, bones and connective tissues.”
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So, how much protein should you have?
The amount of protein you need daily can vary depending on several factors, including your age, activity level and overall health. “Generally, a simple guideline is to consume about 0.8 grams of protein per kilogram of body weight,” advises Riya. “For most adults, this translates to about 50-70 grams of protein per day.”
In food maths, that could be the equivalent of “a chicken breast (about the size of your palm), which typically contains around 30 grams of protein,” Riya explains. “Similarly, a cup of cooked beans or lentils has about 15-18 grams of protein, and two large eggs will give you roughly 12 grams.”
There are some exceptions to this rule. You often need more protein to repair and build muscle after intense workouts, says Riya. “Pregnant and breastfeeding women also require extra protein to support the growth and development of their babies," she adds, as well as those recovering from illness or surgery "to aid in the healing process.”
Similarly, the older you get, the more protein you will need in your diet, as it helps to slow down the loss of muscle mass and strength that comes with age.
It's not just about hitting those numbers, though, Riya notes. “The quality and sources of protein matter, too. Incorporating a mix of lean meats, fish, eggs, legumes, nuts and seeds into your diet can provide you with a full range of amino acids and additional nutrients beneficial for your health.”
When you eat your portion of protein matters, too. “I recommend spreading your protein intake throughout the day to ensure your body has a constant supply," Milena says. "Consuming protein with each meal not only helps to maintain muscle mass, support metabolism and help you feel fuller for longer periods of time, but it also balances your blood sugar.”
It's worth stressing that a life-threatening protein deficiency is rare in the UK. That said, these are the signs that you're not getting enough protein via your diet:
1.Swollen feet and ankles
A common sign that you're not getting enough protein is swelling (also called edema), especially in your feet, ankles and abdomen. This is because a lack of protein affects the balance of fluids in your tissues, says Riya. “Proteins like albumin help manage the balance of fluids between blood vessels and body tissues. Without enough protein, this balance is disrupted, causing fluid to accumulate in the wrong places, leading to noticeable swelling.”
As many things can cause edema, speak to your doctor in case it's a symptom of something more serious.
2. Mood swings
Many neurotransmitters – chemicals that your brain uses to communicate between cells – are made of amino acids. For example, the amino acid tryptophan is a precursor to serotonin, the body's feel-good chemical.
“Protein provides the amino acids crucial for the production of neurotransmitters such as serotonin and dopamine, which are essential for maintaining stable moods,” Milena notes. So a lack of protein can really affect how you feel.
Milena adds that mood changes, such as feeling “hangry” (a combination of feeling hungry and angry), can indicate insufficient protein intake, too. “Protein helps balance blood sugar levels and, with inadequate consumption, your blood sugar can drop, leading to irritability and mood swings.”
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3. Hair, skin and nail issues
Protein is crucial for the health of your skin and hair. “When you're not getting enough protein, your body prioritises the vital functions, which often means your hair and skin get less attention,” Riya says.
The amino acid cysteine is important for the production of keratin, “a key protein in hair, skin and nails,” Milena adds. Without adequate protein intake, your hair growth cycle can become disrupted, leading to increased hair shedding and nails can become brittle.
As for your skin, protein plays a crucial role in maintaining its elasticity and hydration, Riya notes. “A lack of protein can impair collagen production, another protein that keeps your skin firm and supple,” she explains. "This results in dry, flaky skin that might also appear duller. Essentially, ensuring a balanced protein intake supports healthy, glowing skin and strong, thick hair.”
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4. Slow-healing wounds
For similar reasons, not eating enough protein can mean that cuts and sprains take longer to heal. “Protein is essential for tissue repair and the formation of new cells and collagen,” explains Milena. “Insufficient protein intake can lead to slower wound healing and an increased risk of infection.”
5. Weak muscles and feeling tired all the time
If you find you get tired quickly, or frequently have sore muscles, it might be a sign that you're not getting enough protein.
“Protein is crucial for muscle maintenance and repair,” Riya explains. “When you're not consuming enough protein, your body struggles to rebuild muscle fibres, which can lead to muscle weakness and loss. Without adequate protein intake, your energy levels drop significantly because muscles play a vital role in your overall stamina and strength.”
6. Feeling hungry
Protein fuels the body so it will make you feel fuller throughout the day. It also influences certain hormones associated with appetite. Milena points out, “it stimulates leptin, the feel full hormone, and reduces levels of ghrelin, the hunger hormone."
7. More sugar cravings
Eating a meal without enough protein means you digest the carbohydrates more quickly and your blood sugar will rise – and then suddenly plummet.
“Protein helps stabilise blood sugar levels by slowing down the digestion and absorption of carbohydrates,” says Milena. “When you consume protein, it slows down the absorption of sugar into the bloodstream, preventing rapid spikes and crashes in blood sugar that trigger cravings.”
8. Frequently getting ill
A lesser known benefit of eating enough protein is a boosted immune system. “One of its [your immune system's] primary functions is to aid in the production of immune cells and antibodies, which are essential for fighting off infections and illnesses,” Riya notes. “Without sufficient protein, your body might struggle to produce enough of these crucial components, leaving you more susceptible to getting sick.”
Additionally, "proteins help repair body tissues and cells, which is vital when your body is battling an infection,” she continues. “This means that a lack of protein can slow down your recovery process, prolonging the duration of illnesses. On a broader scale, a well-balanced diet, rich in healthy protein sources such as beans, lentils and nuts, supports overall immune health and can even reduce the risk of various diseases.”
The best protein-rich foods
A healthy, balanced diet typically provides all the amino acids your body needs, but only if you add protein to each meal. “Adding protein to your diet is easier than you might think,” says Riya, who recommends these food sources:
Lean meats like chicken and turkey: "They're packed with essential amino acids to help build and repair muscle."
Fatty fish like salmon and trout: “They are not only high in protein but also come with the added bonus of omega-3 fatty acids, which are great for your heart.”
Dairy: “Greek yogurt and curd are also great protein sources. They’re convenient for snacking and can be easily incorporated into meals.”
Eggs: “They are often considered a ‘perfect protein’ as they provide all nine essential amino acids, which your body can't produce on its own.”
Legumes such as lentils, chickpeas and black beans: “As a vegan, I get my protein from plant-based sources that are just as effective and nutritious. These are staples, offering substantial protein content.”
Quinoa: “This is another powerhouse, providing all nine essential amino acids – quite rare for a plant source.”
Nuts and seeds: “Almonds, chia and hemp seeds add both protein and healthy fats to your diet.”
Tofu and tempeh: “These are fantastic soy-based options that can be incorporated into a variety of dishes.”
Spirulina: A type of blue-green algae, "add it to smoothies or take it as a supplement.”
How to get more protein
As well as healthy swaps (for example, swapping cereal for Greek yogurt or eggs at breakfast), consider adding a piece of protein to your regular meal.
“Remember, it’s all about balance and ensuring you get a diverse array of protein sources to meet your nutritional needs,” Riya says. “When you make a salad, top it with grilled chicken, tofu or chickpeas to give it an extra boost. Or, instead of just pasta, why not add some lentils or beans to make it more balanced?”
And, while protein powders are no substitute for a healthy diet, sipping a shake in the morning or post-gym is an easy way to ensure you also get enough protein (Stanley cup and dumbbells are optional).
For more from Fiona Embleton, GLAMOUR's Associate Beauty Director, follow her on @fiembleton.