In this article, I tell you all you need to know about the important macronutrient "protein". Macronutrients are foods we can't live without as they provide us with energy. We distinguish three main macronutrients: "Fats", "Proteins" and "Carbohydrates", which all contain different energy levels (see graph below. As a point of reference, I also added the amount of energy alcohol provides us with). But let's deep-dive into protein now:
We will take a closer look at what proteins/ "amino acids (the fundament of proteins)" are, why they are so important to us, how proteins differ, what levels of protein we should consume to maintain a healthy diet and how we can accomplish this goal, i.e. what foods are great protein sources. This is especially important for those of you, who follow a plant-based or vegan diet as animal products, such as dairy and meat, are the human's classic protein sources and which therefore need to be replaced adequately and in sufficient amounts.
Especially People Who Follow A Plant-Based Diet Should Pay Close Attention To A Healthy Protein Intake
The word protein by itself (meaning "the first" or "most important") already indicates that this macronutrient is essential for our health. Proteins are a fundamental building block of our cells and are responsible for a multitude of functions and processes within our body. For example, proteins are the building material of our tissues (i.e. our skin, muscles, tendons), they form almost all our enzymes as well as some of our hormones, most of our antibodies consist in large amounts of proteins and proteins function as "transport vehicles" for fat (lipoproteins) and oxygen (hemoglobin).
Proteins Consist Of Amino Acids And Can Be Divided Into 3 Main Categories:
Essential Amino Acids, Non-Essential Amino Acids & Semi-Essential Amino Acids
Proteins consist of amino acids which can be divided into three main categories: Essential amino acids, semi-essential amino acids and non-essential amino acids. Non-essential amino acids are amino acids which can be produced by our bodies, are available in sufficient amounts and therefore don't need to be absorbed through the foods we eat. In contrast, essential amino acids cannot be synthesized fully by our body and therefore need to be absorbed through our nutrition. There are 8 essential amino acids we need to provide our body with. Last but not least, the semi-essential form the third amino acid category. Those amino acids can be produced by our body theoretically but may not be available in sufficient amounts. Therefore, we also need to absorb them through our food. The chart below gives you an overview of the different amino acids groups and their category members.
All the foods we eat consist of a different amino acid profile. Therefore, we need to pay close attention what type of protein we provide our bodies with. Key is to consume the 8 essential as well as the semi-essential amino acids in sufficient amounts on a daily basis.
All The Foods We Eat On A Daily Basis Differ In Their Protein Composition
Almost all existing foods contain certain amounts of protein. However, as mentioned in the previous paragraph, they all contain a different amino acid profile and therefore also greatly differ in the amount of protein they contain. Overall, we can distinguish two main categories: Plant Protein sources, such as legumes, vegetables, seeds, nuts and grains and animal protein sources, such as meat, dairy and seafood.
To be very fair here from the beginning, animal protein sources are officially considered "higher-grade" protein sources as their amino acid profile tends to be more similar to our body cells and can, therefore, be transformed more efficiently into endogenous protein than plant protein sources. However, this doesn't mean that we must eat animal products to be healthy. We only need to pay close attention to what kind of protein sources we consume.
If we, for example combine beans and corn, two plant protein sources with a relatively rich and complementing amino acid profile, we naturally increase our body's protein absorption rate according to the law of biological quality. The same holds true to the combination of hummus and wholegrain bread or spinach and almonds. By the way, according to this theory, classic potatoes (even though they only contain around 2g of protein per 100g) have a perfectly balanced amino acid profile and provide us on top with healthy and satisfying carbohydrates. Therefore, no need to ban them from your diet completely. :)
The DGE (German Association for Nutrition) recommends a daily protein intake of 0.8g protein per kg body weight. This means if you weight 50g, you should consume 40g protein per day (0.8x50kg=40g). Calculated into calories, those are 164 kcal of protein per day. However, and here comes the big BUT: You should never consume less than 15% of protein relative to your daily calorie intake. So, don't take the 164kcal per day of protein as your golden guideline, stick to 15% of protein relative to the total amount of macronutrients you consume per day under normal conditions. With "normal" I mean a healthy adult person, who isn't in it's growth stage (kids and teenagers), isn't sick or pregnant and isn't an extreme athlete. For athlete's recommendations vary between 1.2-1.7g per kg body weight.
Under "Normal" Conditions, 15% Of Your Daily Calorie Intake Should Come From Proteins
Protein, as mentioned above, is part of almost every food. However, the crucial "amino acid profile" of the food varies drastically from food to food. Some great protein sources. which don't only contain great amounts of protein, but also other nourishing nutrients, are: hemp, spirulina nuts and seeds in every form and shape, legumes (such as lentils, white beans and lupins), whole grains and pseudo-grains (such as quinoa, oats and whole spelt), as well as veggies and microgreens. Can you believe that leek sprouts contain 4.8g protein per 100g? This is almost twice the amount of potatoes.
The chart below gives you a great overview over the protein sources, I always keep as a staple at home.
1. Book: Vocational Training "Nutritionist" (2020): Reading material: Akademie für Sport und Gesundheit.
2. Niko Rittenau (2019): Book Vegan Klischee Ade!
3. Smarticular (2020): Alle essentiellen Aminosäuren: Diese Pflanzen machen Fleisch überflüssig (13.07.2020)
4. Protein Data Sources: USDA.com, 1001Frucht.de, Nutritional information from purchased goods