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I often talk about the three Cs : confusion, contradict and compromise and to just through the confusion means taking it back to basics. So, I’m going to do a short series on the core foundations of what we find in food ie the macronutrients.

There are three macronutrients: protein, fats and carbohydrates and these are the nutrients we need in the largest amount in our diet.

Protein
Protein containing foods can come from animal sources such as beef, chicken, fish, egg and cheese or from plant-based sources such as beans, lentils, peas, nuts and seeds.

All of these foods contain the building blocks of protein – amino acids – and this is where we start to find the nutrition and health benefits.

Protein in food is made up of chains of amino acids all attached together.  If you imagine a house built of Lego bricks, the house is the protein we find in our food and the individual bricks are the amino acids.

When we eat a protein rich food our digestive system breaks it down into the individual amino acids, these are then re-built or re-connected to make protein structures in our bodies.

Muscles and collagen are well known structural proteins.

The neurotransmitters such as dopamine and acetylcholine are built from small chains of amino acids and are vital for our brain health and emotional health. Amino acids are also the building blocks for digestive enzymes, detoxification molecules.

The big take away is: the need for proteins in our diet is much more than building and maintaining muscle. 

“Complete” protein or protein “quality”
Going back to the Lego bricks analogy, our digestive system breaks up the Lego house into the individual Lego bricks and our body uses those bricks to build new structures.

9 of the amino acids cannot be made in the body and must come from our food, they are: Histidine, Isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine.

If your body is going to be able to build all the structures it needs, it has to have all the amino acids, or “Lego bricks”, available.

The amino acid content varies by protein foods, this means not all protein is equal and makes it harder to estimate exactly how much protein we all need.

Animal based proteins contain an optimal level of all the essential amino acids. The terms “complete protein” or high “protein quality”  are often used for these foods.

Plant based proteins are a little different. While they contain the same amino acids, they are always lower than optimal in at least one of the essential amino acids and are sometimes referred to as “incomplete” proteins.

The quantity of protein found in foods will also vary, depending on the food. The above table provides some examples of the amount of protein found in typical portion sizes of foods.  It is interesting to note that some foods that are often used as examples of plant-based protein (quinoa, lentils, hummus) can actually be quite a bit lower than we might expect.

How much protein are we meant to eat a day?
Having looked at how much protein is likely to be found in different foods, how much of it are we meant to eat in a day?
We need  0.75g of protein, daily, per kg bodyweight.
NB: If you are very active and training hard your needs will rise a little to support the muscle repair.

When to eat protein?
We need a portion of protein with each meal.  But why?
Protein in a meal helps create a sense of fulfilment, a sense of satiety from the meal.  When protein is eaten alongside carbohydrates it helps to ensure the breakdown of the carbohydrates in to sugar and the release of that sugar in to blood stream is more regulated.  In other words, it plays an important part in keeping our blood glucose (sugar) levels steady which is important for health.

My guide is to aim for 16-20g of protein per meal.

Is more always better when it comes to protein?
Once our amino acid needs have been met there is no biochemical advantage to eating additional protein.

In fact there can be negative effects with consumption of high protein diets. It can lead to kidney stones, bone loss, liver function issues and has even been associated with higher rates of cancer.

There can be a “myth” that eating more protein helps to build lean muscle. This is only partly true; lean muscle requires development through resistance work as well as the provision of the raw materials.

In fact, a recent study found that there when comparing total protein intake and lean muscle mass in women, there was an inverse relationship.  When physical activity was also taken into account, there was a positive relationship between total protein intake and lean muscle mass relationship.

Summary
Proteins are key for the amino acids they contain.  Each meal should contain 15-20g of protein (about one quarter of the plate).  This helps ensure you will have enough of the amino acids as well as stabilise blood sugar and give a sense of satiety.

In the coming weeks I’ll cover fats and carbohydrates.

In health and happiness
Ange
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