When talking about Protein, there is actually not much that you need to know, yet it is still a highly discussed topic. From theories like "You need to eat animal products to get your protein" to companies trying to sell you the "one and only" best available protein shake, there are a lot of confusing isolated bits of information and claims out there.
For everyone too lazy to read much - and this gets a bit longer - lets summarize it right here:
In a nutshell
If you make sure you cover 10% of your caloric need with protein, your supply is well covered. Provided you eat with diversity and natural, it is possible whether you do or do not eat animal products. Supplementation is not needed for most of the people if you hit your caloric goal from healthy foods. Unless you are extremely sportive, recovering from an injury, are pregnant or have an extreme metabolism, you don't need to put any special focus on your protein intake.
Instead of chasing high amounts of protein at any cost, you should rather focus on what other nutrients come with your protein, to enable a good calorie vs nutrient balance.
For the curious reader - let's solve this fuzz together and start from the beginning.
What is protein?
Protein, peptide, amino acids. These terms are often used interchangeably, should however be distinguished when talking about the details. The base building block of protein is an amino acid. That's a group of molecules that have in common that they are all built with a nitrogen atom. In our metabolism there are a total of 20 types of amino acids that are relevant.
Out of those twenty there is a group that can be built by our body from carbs, fat and nitrogen. On the other hand some amino acids need to be obtained through food, because we cannot synthesize them. Therefore, they are called essential and are relevant in nutrition.
If you chain two or more amino acids, you get a peptide. Peptides longer than 50 amino acids are finally called protein. Protein then gets used as building blocks in our cells for tissue, skin, blood, enzymes and more. It makes more than 20% of your body mass, but can also be used as an energy source. Protein is not only a component of animal cells, but also occurs in plants and mushrooms. Since proteins get derived directly from the code in the DNA, it makes sense to see them in every living being.
Since we need 8 (or 9, if you count histidine, which is essential during pregnancy and growth) different amino acids from our food, we not only need to make sure to eat enough protein overall, but also in a composition fitting our needs. An indicator for how well a protein fits our needs is defined by the biological value.
The biological value describes how well we absorb the amino acids from food for building protein. The better the composition fits our needs, the more we will be able to make use of. If we are missing one acid, then we cannot build the corresponding protein. So each of the essential amino acids gets compared to our need. If one amino acid, lets say lysine, is less available than all others, it is seen as the bottleneck for building protein and it defines the biological value of the whole food. If you added more lysine to your food, it may surpass the next lowest amino acid and make this the limiting factor.
Food gets rated on a numeric scale by its biological value. A whole egg marks the 100 on the scale. Any food with a less valuable protein profile will be rated on a lower score, anything fitting our needs better, scores higher than one hundred. Anything close to a score of 100 or above it is called "complete protein" colloquially.
Often the biological value is an argument against plant based protein. It makes sense that animal protein gets rated higher, since the protein needed in an animal is more alike our demand than the one needed to build plant parts. This however starts changing if you combine different protein sources, since each type of food has its individual profile. If you eat from various sources during the day, the overall picture of your amino acids scores much higher, in many cases over 100 and therefore are excellent sources of protein.
How we make use of amino acids
The main purpose of amino acids is building protein. This protein then gets used to build and repair cellular structures like tissue, enzymes, blood cells, antibodies and more. Only a small part of the protein gets used as energy. In general, our body is capable of breaking a single amino acid down to use its energy or form glucose from it, which then can be transformed into fat.
When your glucose reserves are filled, this process is rather slow and provide less than 5% of your energy demand. When energy levels are low, because of long exercise, the energy supply from protein can go up to 15% of your need. The transformation of amino acids happens in your liver.
Your body is capable of breaking down ready-to-use proteins even from muscle cells in order to provide energy. Running low on carbs and energy for many days can therefore reduce your muscle mass and metabolism overall.
Through activity, you not only raise the calorie burn, but also stimulate the synthesis of new protein. On the long run, if you manage to consume more protein than you need and provide the right stimulus through exercise, you will be on the good side and gain.
Can I have too much protein?
Like carbs, protein count 4 kcal per gram. Since we only synthesize the protein that we need, meaning we only use it as building blocks for our body when required, excess protein can be transformed to carbs and therefore to fat as well. Too much protein can theoretically lead to a too high caloric intake. In reality this however is barely possible.
First, each macro nutrient radiates a different amount of heat when being burnt. Protein radiates the highest amount of heat when used, then come carbs and finally fats. You can say each nutrient has a different thermogeneis effect. The more heat gets produced, the less energy is available for storage.
Secondly a protein rich meal makes full, so it is hard to over-eat. Unless you excess your overall calories as well, fulfilling your protein requirement twice as high won't have any special effect, in fact there is no scientific evidence that there is any upper limit for the healthy range.
How much protein do I need?
Depending on who you ask, the baseline of the recommended daily protein intake is between 0.8 and 1g per kilogram of body weight. If you assume you weigh 60 kilos, then you need between 48 and 60 grams per day. If you are overweight, you should take your assumed ideal weight as reference. You can use the BMI to estimate your body weight. Give your height and play with the weight until you hit the normal zone.
With a normal, not extra protein rich but balanced diet, you can archive this goal already half-way through the day. Even when consuming much processed food, you arrive above this threshold through the day.
When doing sports or when recovering from an injury or illness, your protein need rises due to the higher demand of protein to rebuild structures. A protein rich diet therefore can improve recovery and muscle growth times.
Calculate how much protein you need
Your body weight
daily need of protein
According to your intensity of training, your protein need can climb up to double of the base value. This may mean that you might want to look a bit after your protein intake. But since with more activity your caloric needs also raise, your intake will automatically follow by eating more overall. Therefore, the general rule is that as long as you make sure you cover at least 10% of your energy needs with protein, you are on the good side.
How can I rate my food in terms of protein?
At a first glance, mostly animal products seem to be rich protein sources. This is often the case, when you look at the protein content per weight. After all, we are not feeling full from being bloated, but from when we receive calories. Take the watermelon as an example again. If you ate half a kilo of this or half a kilo of a pasta, you would definitely feel the pasta, but not the watermelon.
You therefore should not judge your protein contents by weight, but by protein per calories. Let's take for example a whole egg. Per 100g it contains around 13g of protein and 154 kcal in total. Almost one hundred calories out of this come from fat.
If you take Tofu on the other hand, it only brings 8g of protein onto the scale. Since it is low in fat and high in water, 100g only deliver 76 calories. If you eat 200g to approach the same calorie intake as with an egg, you will have consumed 16g of protein. You can assume that the biological value of tofu is lower, so you might benefit less of it. But when considering the biological value, you should not only consider one food on your plate, but the meal as a whole plus what you eat during the day on top of that. Due to the combination of foods on your plate and across all meals, your overall biological value of the day raises with each type of food you consume.
If on the other hand you would cover your whole calorie intake of let's say 3000 kcal with tofu, you would need to eat 3.8 kilos. That would give you a total of 307g of protein, or 5 times your daily need. With eggs, you would reach 311g, but only would need to eat 1.9 kilos.
To come back to real life, let's rather look at how you can estimate whether one food can add up to a good protein balance or is below the threshold. If you consider that protein counts with 4 kcal per gram, you can come up with one easy calculation, which you can apply to what you can read on the nutrition label:
Protein x 4 / kcalPunch this in your calculator and you see if this food is a good source of protein
If you take the tofu example from before, you would calculate 8g x 4kcal / 76 kcal= 0.42. That's the percent of calories from protein of tofu behind the comma. 40% is way above your goal of 10%. This means, you have plenty of room for food that lacks protein and still hit your goal. Egg on the other hand fills 33% of your caloric intake with protein, which is still an excellent value.
So what are good protein sources?
Again, anything that delivers more than 10% of your caloric needs in protein, can be considered as a safe pick. Most of our natural foods easily break the 10 percent hurdle. Even lettuce, with only 1.4g per 100g hit 37% protein per calorie. Some vegetables, like potatoes however are below the threshold. In fruits, you find also many examples that are low on protein. But as long as you eat other stuff besides that, you're good.
If you highly rely on processed and artificially composed foods it may happen you find some bad rated protein. Rice milk for example comes with very low protein. Often it is artificially sweetened and contains added fats, that give it a smooth texture. Or chocolate pudding, which is mainly made from starch and cream. Or plain white flour, which is used for many cheap types of bread. You get the idea. Eat natural and you have no problems finding the right protein. It is more a question about what comes with it in terms of calories.
- Meat, milk products and eggs: High in protein, but also high in fat, especially saturated fat, which you want to avoid. They have a high bioavailability index and can be used as a sole protein source. I however recommend keeping your overall animal product intake low, because many of them are related to long term problems, like cardiovascular disease.
- Fish: Also high in protein, but usually lower in fat than other animal products. They also contain the omega 3 fatty acids DHA and EPA. All in all a good source of protein nutrition wise.
- Nuts & Seeds: High protein content with high fats, but with a slightly lower bioavailability index. You will however find mainly good and essential fats (more about that in the next article), which is beneficial, if you don't overdo it. I recommend to either treat them as a snack or to sprinkle them over your meal. This often works fine on both savoury and sweet dishes.
- Legumes: High amounts of protein, but not a complete protein due to its relatively low biological value. Still, an excellent source due to the low calorie density. You can and should eat plenty of them. In order to make the amino acids complete, you should combine them with some whole grains.
- Whole Grains: Average to low amounts of protein, but still above the 10% hurdle most of the time when in their natural form. You should not rely on them as a direct protein source, but they are still very valuable as a counterpart for legumes. Combined their bioavailability often is higher than the one from eggs. Many highly processed products from flour often are below the 10% hurdle, so better pick whole foods instead of cheap mass-produced junk.
Should I include protein shakes in my diet?
It depends, but in most cases the answer will be no. If you in general follow a balanced diet and eat from whole and diverse food sources, you don't need to supply your protein at all. This applies well, if you generally reach your calorie goal, even if you hit the gym 2 to 3 times a week. It may however be a good addition if you want to achieve extreme goals or cannot profit from healthy sources due to dietary restrictions. Then, protein shakes may be a profitable addition to your diet. Keep in mind that you should not consider them as your main source of protein, but to treat them as a supplement.
You can check the quality of your protein by checking the ingredients and nutrition label: First you can apply the same calculation to check your protein supply. Then you should check if they are high in sugar. The lower, the better. Fat should be low as well.
So a shake on high proteins and long carbs is what you are looking for. Try to buy organic whole food quality, to not miss out on your supply on vitamins and minerals. Try avoiding added sugar.
Also, shakes are often made from a single source of protein like wheat, hemp or peas. The biological value therefore may be quite low, so you should rely on a complementary protein source from other food sources as well in order to get the most out of it.
And remember, just having a protein rich shake won't help you gain muscles at all. First comes training, to trigger the right growth signals. No pain, no gain! Try cover your need with food first, before you start extending your meal with a shake. But when you cover your calorie goal naturally, you should be fine without it.
What else should I know?
If you are doing sport, you should eat after a training to supply your body with what it needs directly after peak time. Having a good protein supply available fast, can improve recovery and reduce post workout fatigue. Make sure to have a complete protein, by combining several sources.
But besides that, that should be it. Eat healthy and balanced, eat enough calories and your game for protein is done. And even if you absolutely must have that shake, the biggest harm only happens in your purse.