Protein explained: How much is enough for muscle, energy and a healthy life? Warning signs you're overdoing it

Protein isn’t just a trendy word in nutrition, it’s a crucial nutrient your body needs every day. Made up of amino acids, which are like tiny building blocks, protein helps build and repair your muscles, skin, hair, and tissues. It’s key to keeping your body growing, healing, and working properly. Without enough protein, your body can struggle to recover from injuries, build strength, balance hormones, and stay healthy.

Why does protein matter?

Your body needs protein every single day because, unlike fats or carbs, it can’t store protein for later. Every cell in your body depends on protein to work properly. Protein is also essential for making enzymes that help with digestion, energy production, and other important functions. Moreover, it plays a key role in producing hormones like insulin and growth hormone, which keep your metabolism and growth on track.

How much protein do you need?

Protein requirements vary widely depending on age, weight, health, and activity level. For most adults, the Recommended Dietary Allowance (RDA) suggests about 0.8 grams of protein per kilogram of body weight per day. For example, a sedentary 70 kg (154 lb) person typically needs around 56 grams daily. However, athletes or those engaging in intense physical activity may require between 1.2 to 2.0 grams per kilogram to support muscle repair and growth.

Given that many people consume convenience-driven diets low in quality protein, prioritising protein in meal planning is essential to overall health.

Animal protein versus plant protein: What’s best?

Animal proteins come from foods like meat, poultry, fish, eggs, and dairy. They’re called “complete” proteins because they contain all nine essential amino acids your body can’t make on its own. Plus, your body usually absorbs them more easily, making them a top pick for athletes or anyone wanting to build or repair muscle. Animal proteins also deliver key nutrients like vitamin B12, iron, zinc, and omega-3s—especially in fatty fish like salmon.

But watch out: Some animal proteins, like red and processed meats, can be high in saturated fat and cholesterol, which may raise your risk of heart disease if eaten too much.

Plant-based proteins come from foods like beans, lentils, nuts, seeds, soy products, quinoa, and whole grains. Most of these proteins are called “incomplete” because they’re missing one or more essential amino acids. But don’t worry—by mixing different plant foods throughout the day, you can get all the amino acids your body needs. Plant proteins are usually low in saturated fat and have no cholesterol, making them great for heart health. They’re also packed with fibre, vitamins, minerals, and antioxidants that help digestion and boost overall wellness.

While animal proteins are absorbed more easily, a well-planned plant-based diet can meet your protein needs and support a healthy gut, which helps immunity and digestion.

Recommended protein-rich foods

Lean meats: Chicken, turkey, and lean cuts of beef supply high-quality protein, iron, and zinc.

Fish: Salmon, tuna, mackerel, trout, and anchovies offer protein plus beneficial omega-3s.

Dairy: Milk, cheese, and yoghurt—especially Greek yoghurt—are great protein and calcium sources.

Legumes: Beans, lentils, chickpeas, and soybeans provide protein, fibre, and nutrients like folate and potassium.

Nuts and seeds: Almonds, walnuts, peanuts, chia seeds, and sunflower seeds are protein-rich with healthy fats; consume in moderation due to calorie density.

Eggs: A complete protein source packed with vitamins, minerals, and antioxidants.

Myths about protein and weight loss

Protein is often connected to building muscle and losing weight, but how it works depends on your personal goals. It helps you feel full longer, protects your muscle during calorie cuts, and boosts your metabolism by making your body burn more calories while digesting it—a process called thermogenesis.

That said, eating way more protein than your body needs won’t automatically build more muscle or speed up fat loss. Extra protein calories can turn into fat. On the flip side, not getting enough protein can cause muscle loss and slow down your metabolism, making it tougher to lose weight over time.

Is too much protein harmful?

While most people tolerate extra protein without issues, chronically high intake can strain kidneys, especially in those with pre-existing kidney conditions. Excessive protein, particularly from animal sources, may cause digestive issues like bloating and constipation if fibre intake is low. Overemphasizing protein can also lead to neglecting fats and carbohydrates, causing fatigue or nutrient imbalances.

Balance is critical: Consuming adequate protein alongside healthy fats, carbs, fruits, and vegetables ensures overall health and avoids these risks.

Protein timing: Before or after workouts?

The once-popular ‘anabolic window’—a 30-minute post-exercise period believed essential for protein intake—is now seen as less urgent. Current research shows muscles remain receptive to protein over several hours, so timing is flexible as long as daily protein needs are met. Both pre- and post-workout protein consumption can support muscle repair and growth.

Common types include:

Whey: Fast-digesting and dairy-based.

Casein: Slow-release protein from milk.

Plant-based: Pea, rice, soy, hemp.

Collagen: Supports joints, skin, and recovery.

But beware: Protein shakes aren’t magic meal replacements. If you’re eating balanced meals, a shake after a light yoga session probably isn’t necessary. Also, watch for artificial ingredients and check with your doctor if you have any digestive troubles or lactose intolerance.

How to use protein wisely:

Protein shakes make the most sense when:

• You’ve had a moderate to intense workout.

• You won’t get a protein-rich meal soon.

• You want to build or maintain lean muscle.

• You’re managing weight and need a low-calorie, filling option.

Otherwise, stick to whole foods like eggs, lentils, yogurt, tofu, or fish, which deliver protein plus a bunch of other nutrients.