How much protein do you need after 40?

Protein has become the nutrient everyone is selling. It is on the yoghurt, on the crisp packet, on the cereal box. Somewhere in that noise, a simple question got lost: how much do you actually need, at 45, with a job, kids at home and two training sessions a week that you are fighting to protect?

The answer is less dramatic than the marketing suggests. It is also more interesting. For most people, this is not about avoiding a deficiency. It is about the gap between eating enough to stay healthy and eating enough to build.

What the recommendation actually says

The UK reference nutrient intake for adults is 0.75 g of protein per kilo of body weight per day, set by the Committee on Medical Aspects of Food Policy and maintained by the Scientific Advisory Committee on Nutrition. At 80 kilos that is 60 g. In practical terms the RNI works out at roughly 56 g a day for an average man and 45 g for an average woman. The Nordic Nutrition Recommendations put their reference value slightly higher at 0.83 g per kilo, and express the same idea as a share of energy: 10 to 20 per cent of your calories should come from protein.

A reference intake is not a target. It is the level that covers the requirement of virtually every healthy adult in the population. It is the number that keeps you in nitrogen balance. It says nothing about what is optimal when you are also trying to rebuild muscle you have lost since your thirties.

That is where the whole misunderstanding lives. The recommendation is a floor. The argument about 1.6 or 2 g per kilo is about something else entirely: what it takes to get the most out of training. Two different questions, two different numbers.

You are probably already eating more than the minimum

The National Diet and Nutrition Survey puts average protein intake in the UK at about 76 g a day for adults aged 19 to 64, and about 67 g a day for those aged 65 and over. That is roughly 17 per cent of energy, comfortably inside the recommended range and well above the RNI. Swedish national survey data tells the same story, with average intakes around 1.1 to 1.2 g per kilo.

That is worth pausing on. You are very likely above the reference intake already, without having thought about it once. Protein deficiency is rare in healthy adults in this part of the world.

So why bother at all? Because 1.1 g per kilo is enough to keep you healthy but not necessarily enough to get full value out of your strength training. The gap between where you are and where you might want to be is often 30 to 40 g a day. That is a yoghurt and an egg, not a lifestyle overhaul.

Why the number rises with age

Muscle is broken down and rebuilt constantly. After a meal containing protein, the rebuilding side rises for a few hours. What changes with age is how strongly your body responds to the same amount of protein. The phenomenon is called anabolic resistance.

Research on muscle protein synthesis suggests that maximal stimulation is reached at roughly 0.24 g of protein per kilo of body weight in a single meal in young adults, while older adults need closer to 0.40 g per kilo for the same response. Same food, weaker response. The body needs a louder signal before it starts building.

This is why the recommendations for older adults sit higher. The Nordic Nutrition Recommendations 2023 suggest around 18 per cent of energy for the 65-plus group, which corresponds to about 1.2 g per kilo of body weight. The international PROT-AGE expert group recommends 1.0 to 1.2 g per kilo for healthy people over 65, and at least 1.2 g for those who exercise.

At 45 you are not there yet. The point is the direction of travel. Anabolic resistance does not arrive as a notification on your birthday; it creeps in over decades. Your forties are not the decade when the number has to be high. They are the decade when the habit gets built, while it is still easy.

The same is true of muscle mass itself. After thirty, an adult loses a few per cent of muscle mass per decade, and strength falls faster still than mass does. We go through the mechanism in detail in the guide to strength training at home without equipment. Protein is the raw material for that build. Training is the order that gets placed.

How much you actually need

Work from your body weight. The middle column is the reference intake, the floor. The right-hand column is the level beyond which more protein stops adding muscle when you are also strength training.

The 1.6 figure comes from a meta-analysis in the British Journal of Sports Medicine that pooled 49 studies with 1,863 participants. It found that protein intake beyond roughly 1.62 g per kilo of body weight per day produced no further gains in fat-free mass in people who were resistance training. The uncertainty around that breakpoint extends up towards 2.2 g, which is why you see both numbers quoted.

Read that sentence again: in people who were resistance training. The meta-analysis measured the effect of protein combined with training. Without the training there is nothing to measure.

Where the protein actually is

Most people overestimate how much they get from snacks and underestimate how much sits in ordinary meals. Here are approximate amounts in portions that genuinely turn up in a fridge.

Look at that table with one question in mind: how many of those rows appear in your ordinary day? For most people the bulk of it sits at dinner. Breakfast and lunch are where the gap is.

If you eat vegetarian

Plant protein works perfectly well. Two things set it apart from animal sources. The leucine content is usually lower, which means a weaker signal to the muscle for the same amount of protein. Digestibility is slightly lower too.

The fix is not complicated. Eat a little more in total, vary your sources across the day and lean on the strongest plant options: soya products, tofu, tempeh, lentils and beans. Pulses combined with grains cover the amino acid profile well across a day. You do not need to assemble it within a single meal.

Does the timing across the day matter?

Here I want to be straight with you, because this is one of the few places where the popular literature is more confident than the research.

The theory says you should spread protein evenly across three or four meals, since each meal needs to clear the threshold to switch on rebuilding. Observational studies support that picture: older adults with an even spread do better than those who take almost all of it at dinner.

But a randomised trial in 24 healthy people aged 65 to 80 compared an even spread with a skewed one, holding the daily total the same. It found no difference in muscle protein synthesis. The researchers also cautioned that the result should not be carried over to situations where total intake is substantially lower, or to highly active people.

So here is where I land practically. The daily total is the part that certainly matters. The spread is probably a smaller effect, but it costs you nothing to get right, for a simple reason: the most common cause of missing your daily total is a breakfast containing 5 g of protein. Fix breakfast and you usually fix both the spread and the sum in one move.

A sensible benchmark is 25 to 30 g at each main meal. That is one portion of something from the table above, not a calculation.

Five ways to get more in without redesigning your life

This is not a diet overhaul. It is five swaps that add up to roughly 40 g between them.

1. Change breakfast, not lunch. Porridge made with milk lands at around 10 g. The same porridge with 200 g of skyr alongside lands above 30. It is the single biggest lift available to you in one morning.
2. Decide the protein first. Choose the protein source before you choose anything else in a packed lunch. It sounds trivial. It is the difference between a lunchbox with 15 g in it and one with 35.
3. Cook double at dinner. Fry four chicken breasts instead of two. Half becomes tomorrow's lunch. It saves you time as well, which is the whole point in a week that is already full. We have written more about that logic in the guide to training when you have no time.
4. Rebuild the snack. Fruit is good for plenty of reasons. Protein is not one of them. An egg, a handful of nuts or a glass of milk alongside changes what the snack is doing entirely.
5. Add pulses to what you already cook. A tin of lentils in the bolognese, chickpeas in the stew. Nobody at the table will remark on it. You gain 10 to 15 g for free.

What protein does not do

An honest list is more useful than a promise.

It builds no muscle without training. Protein is building material. Training is the order that tells your body to build. Without that signal the surplus gets used for something else. If you take only one thing from this article, do two strength sessions a week and forget about counting grams.

Protein powder is not magic. It is dried milk protein or plant protein in a tub, which is to say a convenient way to get 20 g without cooking. Nothing more. If you hit your target with ordinary food, you do not need it at all.

More is not better past the ceiling. The meta-analysis above found no additional muscle gain beyond roughly 1.6 g per kilo. Going from 1.6 to 2.5 g costs money without returning anything in muscle.

It does not replace sleep. A great deal of the rebuilding happens while you are asleep. Eat perfectly on five hours a night and you are working against yourself. More on that in the guide to sleeping better after 40.

Is too much protein dangerous?

The most common worry is about the kidneys. The idea dates from the 1980s and rests on the observation that the kidneys work harder when handling more protein.

A systematic review and meta-analysis published in the Journal of Nutrition pooled 28 studies with 1,358 participants. It compared higher protein intakes with normal or lower ones in adults without kidney disease. The conclusion was that higher intakes did not affect kidney function as measured by glomerular filtration rate.

For a healthy adult, then, there is no evidence that an intake in the range described here harms the kidneys. Two important exceptions still apply. If you have diagnosed kidney disease the picture is completely different, and the amount of protein you eat should be decided together with your doctor. If you have diabetes or high blood pressure it is sensible to check before making a large change, since kidney function needs monitoring.

Beyond that there is a practical ceiling. Eat a great deal more protein and it starts crowding other things out: fibre, fruit, vegetables and the carbohydrate that makes a running session work. A diet built around a single nutrient gets worse, not better.

When to see a doctor

This article is general health information. It is not a diagnosis and not personal medical advice. Contact a healthcare professional if any of the following applies to you:

• You are losing weight without trying, or your appetite drops for an extended period.
• You are losing strength or muscle quickly without any change to your training or your food.
• You have diagnosed kidney disease, diabetes or high blood pressure and are considering more than a marginal change to your diet.
• You are pregnant or breastfeeding, or being treated for a condition where diet plays a part.
• Thoughts about food, weight or numbers are taking up more space than you want them to. That on its own is a reason to talk to someone, whatever the scales say.

Frequently asked questions

How much protein do I need per day?

The UK reference nutrient intake for healthy adults is 0.75 g per kilo of body weight, which is 60 g for someone weighing 80 kilos. That is the floor that covers your requirement. If you strength train and want the most from that training, the point where extra protein stops building extra muscle sits at roughly 1.6 g per kilo, about 128 g for the same person.

Can I get enough protein from ordinary food?

For the vast majority, yes. UK survey data puts average intake at about 76 g a day for adults aged 19 to 64, comfortably above the reference intake. Reaching 1.6 g per kilo does take deliberate planning at breakfast and lunch, but it can be done entirely with staples like skyr, eggs, cottage cheese, fish, chicken and pulses.

Do I need protein powder?

No. Protein powder is a convenient way to get around 20 g without cooking, and nothing more. It has no properties that ordinary food lacks. If you reach your target with food you were going to eat anyway, the tub is an unnecessary expense.

Does it matter when in the day I eat protein?

The daily total is the part that certainly matters. A randomised trial in healthy people aged 65 to 80 found no difference in muscle protein synthesis between an even and a skewed spread of the same daily total. A benchmark of 25 to 30 g per main meal is still useful in practice, mainly because a low-protein breakfast is the most common reason the daily total comes up short.

Is eating a lot of protein dangerous?

Not for healthy kidneys. A meta-analysis of 28 studies with 1,358 participants found that higher protein intakes did not affect kidney function in adults without kidney disease. If you have diagnosed kidney disease, diabetes or high blood pressure, changes should be made in consultation with your doctor.