Protein: far more than building material for muscle

When protein comes up, most people think first of the gym, muscle and protein shakes. In truth protein is one of the body’s fundamental building materials, and getting enough of it matters whether your goal is to build muscle, lose weight, support an active life, or simply feel good day to day.

Our muscles, skin, hair and nails need protein, and so do our enzymes, hormones, immune system and nervous system. The protein content of a meal also affects how full you feel, and – together with the other nutrients – how your blood sugar behaves after eating.

What are proteins, and why does the body need them?

Proteins are made of amino acids. Think of them as small building blocks the body uses to make the proteins it needs.

The human body uses 20 amino acids to build proteins. Nine of them are called essential amino acids, because the body cannot make them in sufficient quantity on its own and they have to come from food.

Proteins have a great many jobs in the body. They are needed for:

• building and repairing muscle and other tissue;
• producing enzymes and many hormones;
• the normal functioning of the immune system;
• transporting various substances around the body;
• maintaining the structure of skin, hair and nails;
• the normal functioning of the nervous system;
• preserving muscle mass and physical capacity as we age.

So protein is far from being just “muscle food”. Having enough amino acids available is necessary for the whole body to work as it should.

Protein and muscle mass – it matters even if you don’t want bigger muscles

Muscle tissue is in constant flux. The body breaks down old proteins and builds new ones in their place, and it needs amino acids from food to do it.

Holding on to muscle becomes especially important with age. Muscle mass starts to decline gradually in adulthood, and as we get older muscle tissue becomes less responsive to the stimulus of both dietary amino acids and training.

That is why resistance training and adequate protein intake make such a strong combination for maintaining muscle mass, strength and functional capacity.

Muscle is not only a question of appearance. It is what lets us move and manage everyday tasks, it supports the skeleton, and it is an important part of metabolic health. Muscle tissue is also one of the main places where the body uses glucose from the blood.

Protein helps you stay full for longer

One of protein’s most practical qualities is its effect on satiety.

Protein is generally a more filling macronutrient than carbohydrate or fat. A meal with enough protein in it can help you stay full for longer afterwards and reduce the urge to snack again soon.

This matters especially when the goal is weight loss. In an energy deficit the body has to take in less energy, but constant hunger makes that kind of eating hard to stick to.

A diet with enough protein has two important advantages here: it can support satiety, and it can help preserve muscle mass while you are losing weight.

What is the connection between protein and blood sugar?

When we eat carbohydrates, most of them are broken down during digestion into glucose, which enters the bloodstream. But how quickly and how high blood sugar rises after a meal depends on far more than the grams of carbohydrate alone.

What matters is the composition of the whole meal – the type and amount of carbohydrate, the fibre, the protein, the fat, and how processed the food is.

When a carbohydrate-rich food is part of a mixed meal that also contains protein, fibre and fat, the glucose response afterwards can differ from eating fast-absorbing carbohydrate on its own. Protein also stimulates insulin secretion, which is a normal part of the body’s metabolism.

So the aim is not to fear carbohydrates or cut them from the menu, but to put together a balanced meal. There is a real difference between a snack that is just a bread roll and one that is wholegrain bread with egg or cottage cheese and some vegetables alongside.

A good practical question to ask of any meal containing carbohydrate is: where is my protein and my fibre?

Blood sugar, energy and how you feel

A healthy person does not need to keep blood sugar in a perfectly flat line all day. A rise in glucose after eating is a normal physiological response.

What can happen, in some people, is that meals made up mainly of quickly digested carbohydrate with little protein or fibre leave the stomach empty sooner. The result can be hunger returning, a craving for something sweet, or a sense that energy levels swing through the day.

A balanced meal with protein, fibre-rich carbohydrate, vegetables and a sensible amount of fat often helps you stay full longer and supports a steadier energy level.

So it is worth starting the day not only with “what shall I have for breakfast?” but also with “where is the protein in my breakfast?”.

Does protein affect our mood as well?

There is an important link between proteins and the brain, too.

Amino acids are not only building material for muscle. Some of them are precursors to compounds the nervous system uses to pass on signals.

The amino acid tryptophan, for example, is the precursor for serotonin synthesis, and tyrosine is used to synthesise dopamine and noradrenaline among others.

That does not mean eating more protein automatically makes us happier or more energetic. Mood and mental wellbeing depend on many things – sleep, stress, physical activity, health, energy intake and the overall pattern of your diet.

What is true is that the nervous system needs enough nutrients, amino acids among them, to function normally. That is one more reason to see protein as much more than a macronutrient for athletes.

Digesting protein costs the body more energy

Digesting food takes energy in itself. This is known as the thermic effect of food.

Compared with fat and carbohydrate, the body spends relatively more energy digesting, absorbing and metabolising protein.

That does not make protein a “fat burner”, but together with greater satiety and the preservation of muscle mass it is one of the reasons why getting enough protein matters when you are working on body composition.

How much protein do we actually need?

There is no single number here that suits everyone.

Protein needs are influenced by, among other things:

• body weight and body composition;
• age;
• level of physical activity;
• the type and volume of training;
• daily energy intake;
• state of health;
• the goal – building muscle, maintaining it, or losing weight, for example.

An adult’s minimum protein requirement and the optimal amount for an active person are not necessarily the same thing.

For people who train regularly, a figure of roughly 1.2–2.0 grams of protein per kilogram of body weight per day is often used as a guide. With resistance training, an energy deficit, or the goal of preserving muscle mass, the right amount may sit at the higher end of that range.

For an active person weighing 70 kg, for instance, 1.6 g/kg works out at about 112 grams of protein a day.

More is not automatically better, though. Once the body is getting enough protein, pushing the amount higher and higher does not necessarily bring better and better results. There has to be room on the plate for other important nutrients too.

Spreading protein through the day matters as much as the daily total

If your daily target is, say, 120 grams of protein, the most practical route is not 5 grams at breakfast, 15 at lunch and an attempt to make up the rest in the evening.

It is better to spread protein across several meals through the day.

Across four meals, 120 grams of protein would mean roughly 25–35 grams per meal. With a higher body weight and a higher protein intake the per-meal amounts are of course larger.

The exact optimum depends on the person, but the practical principle is simple: a protein source should be a natural part of every main meal.

What are good sources of protein?

Good-quality animal sources of protein include:

• fish and seafood;
• eggs;
• chicken and other poultry;
• meat;
• quark and cottage cheese;
• skyr and Greek yoghurt;
• other protein-rich dairy products.

From plant sources, it is worth adding:

• beans;
• lentils;
• chickpeas;
• soya and soya products such as tofu and tempeh;
• peas;
• wholegrains;
• nuts and seeds.

On a plant-based diet it is worth using a variety of protein sources through the day. You do not have to get every amino acid you need from one food, or even from one meal – what counts is the diet as a whole across the day.

How is the SmartFOOD protein package put together?

The SmartFOOD protein package is built on these same principles.

Its daily energy is divided roughly in the ratio:

30% protein / 40% carbohydrate / 30% fat.

It is worth stressing that 30/40/30 refers to the share of energy coming from each macronutrient, not the ratio of their weights in grams.

For example:

• 1 gram of protein gives about 4 kcal;
• 1 gram of carbohydrate about 4 kcal;
• 1 gram of fat about 9 kcal.

So 30% of energy from protein already amounts to a substantial daily intake. On a 2000 kcal menu, 30% protein comes to roughly 150 grams of protein a day. Even on a lower-calorie menu the daily amount can exceed 120 grams.

Why this particular split?

The point of a high-protein menu is not to crowd out carbohydrate or fat. All three macronutrients have their own important role in the body.

Protein supports the maintenance and recovery of muscle mass and contributes to satiety.

Carbohydrate is an important source of energy for the body and supports both everyday activity and training capacity.

Fat is needed for building cell membranes and absorbing fat-soluble vitamins, among other things.

The SmartFOOD protein package is also designed so that protein does not pile up in a single meal but is spread across the day’s meals. That way the body gets amino acids regularly through the day, and reaching an adequate daily total becomes far easier. “High protein”, then, does not simply mean a bigger piece of meat on the plate or taking carbohydrate off the menu.

The goal is a balanced, considered menu in which enough protein, good carbohydrate sources, fibre and the fats you need all form a single whole.

Start with one simple question

You do not have to change your whole menu overnight to start eating better.

Look at your next meal and ask: where is my protein?

Then check whether the plate also has vegetables or other fibre-rich food, a good carbohydrate source, and a sensible amount of fat.

Applying those few simple principles consistently is often enough to make the whole day’s eating considerably more balanced.