How Much Protein Do You Need a Day? (For Muscle and Weight Loss)

A practical guide · about 7 min read

Protein is having a moment. It is on every food label, in every shake, and at the centre of most fitness advice. But behind the hype is a real question with a clear, evidence-based answer: how much protein do you actually need each day? The number depends on your goal, and getting it right helps you build muscle, lose fat, and stay healthy. This guide gives you the targets, backed by research, in plain terms.

Start with your body weight

Protein needs are best expressed in grams per kilogram of body weight, because a 60 kg person and a 90 kg person clearly need different amounts. From there, your goal sets the target:

For a 70 kg person, that means about 56 g just to avoid deficiency, but roughly 112 to 154 g per day to build muscle or protect it during weight loss. In pounds, the muscle-building range works out to roughly 0.7 to 1 gram per pound of body weight, which keeps the mental maths easy.

The science behind the numbers

These are not guesses. A landmark 2018 review of 49 studies with over 1,800 participants found that muscle gains kept improving as protein rose, up to about 1.6 g/kg per day, after which the benefit levelled off. A larger 2022 analysis of 74 trials confirmed that intakes at or above 1.6 g/kg produced the most consistent lean-mass gains. The upper ceiling of around 2.2 g/kg is where extra protein stops adding meaningful muscle. Notably, the 2026 US Dietary Guidelines moved the general recommendation up to 1.2 to 1.6 g/kg, catching up with this evidence.

Why you need more protein to lose weight, not less

This surprises people: when cutting calories, you should eat more protein, not less. Here is why. In a calorie deficit, your body can break down muscle for energy. Higher protein protects against this. In one study, dieters on low protein (1.0 g/kg) lost about 1.6 kg of muscle, while those on higher protein (2.3 g/kg) lost only 0.3 kg. Protein also has two fat-loss superpowers: it is the most filling of the three macronutrients, so you feel satisfied on fewer calories, and it has a high thermic effect, meaning 20 to 30% of its calories are burned just digesting it, compared with under 10% for carbs. See our guide on calories for weight loss for how this fits your overall plan.

Does timing and spacing matter?

You have probably heard that "your body can only absorb 30 g of protein at once." That is a myth. Your body absorbs far more than that; the 30 g figure relates to how much maximally triggers muscle building in a single meal, not what you can digest. That said, spreading protein across your meals is still sensible, aiming for a solid serving at each of three meals is a practical approach, and it is easier on digestion than one giant portion. The most important thing, though, is hitting your daily total; distribution is a fine-tuning detail.

Protein sources matter too

Not all protein is equal. Animal sources such as meat, fish, eggs, and dairy are "complete," containing all the essential amino acids, and are absorbed at around 95%. Plant sources like beans, lentils, tofu, and grains are excellent for health and fibre, though most (soy being an exception) are lower in one or more amino acids and absorbed slightly less efficiently, around 75 to 80%. If you eat plant-based, simply combine varied sources across the day and aim a little higher on total intake.

Can you eat too much?

For healthy people, moderate high-protein diets appear safe, and studies have found no fat gain even at intakes well above the ceiling. The main cautions are for those with existing kidney conditions, who should follow medical advice, since the kidneys work harder to process protein waste. For everyone else, going a bit over your target does no harm; it simply offers no extra muscle benefit. As always, big dietary changes are worth discussing with a doctor or dietitian.

Work out your target

To turn this into a personal number, multiply your body weight in kilograms by the figure for your goal. Then fit it into your overall calories: use our Calorie Calculator to find your daily energy needs, and aim to get a good share of them from protein. Combined with the right calorie level, hitting your protein target is one of the most reliable ways to change your body composition.

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