Protein - What? Why? Where?
I'm sure you've heard about protein many times before- and perhaps you associate it with bodybuilders showing off their weightlifting skills. And they will all certainly be thinking about their daily protein intake!
But perhaps there are also many of you who aren't so sure about what protein actually is, why the body needs it and which foods to find it in. So read on to find out more!
The energy or calories from our food come from three primary macronutrients: carbohydrates, fats and protein. "Macro" means large, and these basic nutrients are needed in large quantities to keep us alive and healthy. So protein is one of them, and together with water it actually makes up a major part of our body!
The word itself comes from the Greek word "proteios", meaning "primary" or "taking first place", and it's essential for a vast range of vital bodily functions including growth, repair and maintenance of body structures. Nearly half of the protein in our body is in skeletal muscles, about 15% in the skin, another 15% is in blood and the remainder is mostly in organ tissue. That's already telling us what it might be useful for!
If you've read my previous blog entry on sugar then you might remember that carbohydrates get broken down into glucose molecules. Proteins on the other hand are made up of a rather large number of amino acids. Proteins can contain hundreds to thousands of these amino acids in varying combinations. There are also different types of amino acids- some which the body can make itself and others which we need to get from our diet- we call the latter essential amino acids.
So we know that protein is one of the primary three macronutrients- but what is it good for?
- Tissue growth, repair and maintenance
For example think of growing children, strong nails and hair, good body posture.
- Regulation of metabolism
Enzymes make biochemical reactions happen inside our body, for example digesting food or using nutrients to create energy. Well enzymes are proteins! And furthermore, a lot of hormones are derived from proteins, such as insulin.
- Muscle contraction
You wouldn't be able to move your muscles without adequate protein.
Antibodies which help protect us against pathogens depend on protein. Catching lots of infections may be a sign of low protein availability (among other possible root causes).
Protein is needed to help break down substances in our bodies that we don't really want to store inside us, such as heavy metals or other potentially harmful substances.
- Brain function
Certain types of amino acids are used to make neurotransmitters and these are absolutely vital for brain function, cognition and mood. Serotonin, for example, has effects on appetite, sleep, mood, memory, learning and behaviour.
- Blood sugar control
Again, this one links in with my previous blog post on sugar. Protein requires quite a long time to digest and so combining carbohydrates with protein is likely to reduce big spikes in your blood sugar levels and you might instead get a more even supply of energy.
Protein can help you feel full for longer, so adjusting your protein intake might help if you're looking to loose weight.
Phew! Quite a list- and there are still more reasons why protein is important for our health. There obviously isn't a need to remember all of those, but the message to take home is this:
Some proteins have all the essential amino acids (the ones the body cannot make itself) and these are called complete amino acids.
Sources of complete amino acids include eggs, dairy products, meat and fish. Soy products, too, offer complete proteins (but some people do not tolerate them well). Perhaps you've heard of quinoa or even amaranth- these grains contain all the essential amino acids but the overall protein intake is still relatively low so try to combine it with other proteins!
Plant based protein sources include legumes (lentils, peas, beans), nuts and seeds and to a lesser degree grains. These foods however do not offer all the essential amino acids, so you need to try and combine them with other protein foods, for example by combining:
- legumes with seeds (adding for example sunflower seeds to dishes containing beans)
- legumes with grains (such as rice and bean dishes)
You don't necessarily have to do combine plant based proteins at every meal but try to get a range of different proteins throughout the day. As always: the more variety, the better.
Some people also use protein powder, for example in healthy smoothies, to help get sufficient protein or perhaps you've heard of the tiny algae spirulina. They can be particularly interesting for vegetarians and vegans.
Now, some people might react to some of the foods listed above. Lentils and beans, for example, cause discomfort for some but are fine for others. So as said before: There is no one-size-fits-all diet. See what works for you and get advice if needed.
Lastly- how much do we need?
Difficult to answer on a generic level as this will vary from person to person. It depends on your activity level, your age and also on any symptoms you might be dealing with. As just mentioned, some people struggle to digest certain protein rich food sources (and that's what nutritional therapists often deal with). But anyway, try to fill about 20-30% of your plate with good quality protein. It doesn't have to be fancy. Our diets often tend to be very rich in starchy carbohydrates- bread, pasta, rice, potatoes. Make sure you always have a source of protein on your plate and try to add variety!