How much protein do you actually need?

When it comes to basic nutrition, there’s arguably no more important building block than protein.

Protein, as many of us know, is essential for repairing and rebuilding muscle tissue, but it also serves other crucial purposes. You need protein to make organs and skin. You need protein to produce hair, blood, and connective tissue. Protein produces enzymes and neurotransmitters. It also helps to keep your immune system in top shape.

Protein itself is made up of smaller molecules known as amino acids. To function properly, the body needs 20 different amino acids. The irony is that while the body makes hundreds of amino acids in the course of a day, it’s unable to make nine of the so-called essential amino acids.

We get those amino acids from foods, and they have big jobs. Isoleucine, for instance, aids in the production of haemoglobin, while leucine is the amino acid that helps grow and repair muscle tissue.

So here comes the inevitable question:

How much protein do we really need?

It actually isn’t all that complicated, although the rules, so to speak, change as we age or if we spend hours at the gym each week. The DRI (Dietary Reference Intake) for protein is around 0.35 grams of protein per pound (0.75 grams per kg) of body weight per day.

So a person that weighs 75 kg (165 pounds) should consume an average of 60 grams of protein per

day. Since there are approximately four calories per gram of protein, 60 grams of protein would result in the intake of 240 calories.

But this can be easier or harder depending on your usual diet. Generally, animal protein provides all essential amino acids in the right ratio for you to make full use of them. An 85 gram (3-ounce) serving of salmon contains 19 grams of protein. The same serving of skinless chicken breast contains 27 grams of protein. So if you’re eating animal products like meat, fish, eggs, or dairy every day, you’re likely getting enough protein.

Some plant sources - soy protein, quinoa and Quorn - also contain all the essential amino acids needed for good health but others lack one or more of the essential amino acids. Sometimes animal protein is thought of as a ‘complete protein’ for this reason, but it’s not true that vegetarians will lack protein, or that you need to eat plant-based proteins in certain combinations. Eating a variety of plant protein each day will give you all the essential amino acids you need.

When you might need more

However, as we age, we need to increase our protein intake. From around 50 years of age, we need to increase the protein in our diets to one gram per kilogram of our body weight to maintain muscle mass.

People that exercise regularly also need to eat more protein than the recommended daily intake.

To increase muscle mass in combination with physical activity, it is recommended that a person that lifts weights regularly or is training for a running or cycling event eat a range of 1.2-1.7 grams of protein per kilogram of body weight per day (or 0.5 to 0.8 grams per pound) of body weight. This higher number is because when you’re exercising hard, you’re breaking down muscle, so you need to build it back up.

Consequently, that same 75 kilogram person in our example about should increase their protein intake to 75 grams (300 calories) to 128 grams (512 calories) in order to gain muscle mass. Shakes and supplements can be helpful but, as usual, whole foods are generally better and this level of intake can generally be met through diet alone and without additional protein and amino acid supplementation.

Many of the amino acids from a protein shake or other similar sources are simply secreted in the urine. Also keep in mind that protein doesn't do much without the workout beforehand so if you’re an average guy who’s not exercising a lot, sitting on a sofa and drinking protein shakes isn’t going to give you bulging biceps.

But when you’re eating a high-protein diet, you should also think about what else is - or isn’t - in your diet. Vegetables and other high-fibre foods should also be a part of your meals. You won’t get that if you’re eating a baked potato and a tomahawk steak (no matter how delicious that is on its own).

Another important factor is how much protein the body can effectively use.

Our bodies have an endless capacity for holding onto fat, but they don’t store protein. It’s being used constantly throughout the day. But eating more protein than you need - a hallmark of the keto diet for example - will lead to that protein being converted into glucose for energy, or worse.

Some research suggests there may be an “anabolic window” such that protein intake within an hour of exercise has the greatest influence on resistance training adaptations but it’s better to spread out your protein intake out throughout the day, frequently eating some protein over the course of different meals, especially if you’re working out a lot and need to keep repairing muscle.

Some eggs in the morning, a piece of fish at lunch, and a dinner plate with, say, chicken, broccoli, and rice is the way to go. If you don’t spread out your protein intake, your body’s not going to use it all. So your body is going to store it - as fat.