Do you know why our bodies need protein, carbs, fat, vitamins and minerals and fibre? … and what it does with each of these?
Alan came to me a few days ago with the following slightly strange question:
What unique food, on top of water, could he eat at every meal and nothing else to simplify his diet?
In fact, with his recent fixation on diets and coupled with his love for systems and simplicity, Alan wanted to simplify things even further and even told me that he’d been thinking a lot about sheep that day! Sheep just eat grass he said – what is the minimum we need to eat to survive and stay healthy, just like a sheep?
Of course he knew we are very different from sheep but he wanted to know how much we could simplify our diet.
I couldn’t (and still can’t) see the appeal of such a boring diet as I love food’s diversity, different tastes and textures but, I suppose, one single food means that shopping and cooking become extremely easy, fast and removed of all thought process.
But…. there is a good reason why humans need a variety of food and that is to provide the body with the 3 macro-nutrients (protein, fat, carbohydrate), the micro-nutrients (vitamins, minerals) and the fibres it needs.
Here is my simplified guide to understanding basic nutrition principles.
Our body is just like an engine. It needs fuel to work. Food is OUR fuel. We consume it, transform it, use what we need, store the excess, reject what we don’t need. But, we’re a bit more complicated than machines because we’re made out of living components. So, we need a complex fuel containing different elements that can fulfill different roles.
Proteins are found in meat, fish, eggs but also in plants (soy, beans, nuts and in smalller quantities in vegetables and fruits). Through the digestion process, proteins are broken down into amino-acids.
Why do we need amino-acids?
Amino-acids are the building blocks with which we are built. Hormones, hair, tendons, organs, enzymes, bones, muscles, etc… are made out of amino-acids. Proteins are particularly needed in periods of growth and wound healing.
What happens if we do not eat proteins?
There are 9 essential amino acids that the body cannot make out of other sources. The body must get them through the food we eat in order to remain healthy. Lack of these essential amino acids leads to growth problems, increased risk of diseases, low energy, increased stress. Complete lack of protein can cause growth failure, loss of muscle mass, decreased immunity, weakening of the heart and respiratory system, eventually death.
How much protein do we need?
The recommended amount is 0.8 to 1.8g per kilogram of our weight a day depending of how active we are (0.8 for not active to 1.8 extremely active).
Lipids can be divided into two groups: oils, which are liquid at room temperature (they can be unsaturated or polyunsaturated) and fats, which are solid at room temperature (they are usually saturated). The fats most relevant to humans are called fatty acids, some of which can be made in the body but others need to be included via the diet – essential fatty acids.
Why do we need fatty acids?
Because they provide a larger amount of energy per gram than carbohydrates and proteins, they are an efficient energy storage system. They play a role in improving the digestion and metabolism of certain nutrients and in the absorption and transport of others, including fat-soluble vitamins. They have protective abilities for organs and provide insulation for the body.
What happens if we do not eat fats?
Let’s be more precise: not all fats are good. Transfats (also called hydrogenated) should be avoided (see our article: “Ban Trans Fats…” on the subject). Saturated fats (fat in meat, dairy products,…), you can eat less of as they increase your bad cholesterol levels. However, unsaturated fats (avocado, nuts, oils, oily fish,…) are beneficial to health and without the essential fatty acids they contain, we would run out of the building blocks needed by cells to maintain health.
How much of these healthy fats do we need a day?
40 to 70 g per day according to your gender/weight.
The body, through the digestion process, breaks carbohydrates (pasta, cereals, rice, potatoes, vegetables, fruits) down into glucose.
Why do we need glucose?
Glucose is used as energy by all the cells in the body. Muscle cells consume glucose for muscle movement. The brain is the top consumer of glucose (20 to 25% of glucose consumption is made by the brain).
What happens if you consume no carbohydrates?
Unlike, proteins and fats, lack of carbohydrates does not end up in death because the body can use other sources of energy:
- red blood cells will use glucose produced from amino acids (proteins you ingest or your own muscles)
- the other cells including the brain will use ketones (produced by the breaking down of fatty acids – fats stored in your body or ingested)
So, why do we need carbohydrates????
We do not need them to survive but we do need them for a healthy life.
- Because of what else carb foods contain: They contain fibres and a large variety of vitamins and minerals (which benefits many internal processes and contribute to a healthy life).
- Because, if we eat less carbs, we’ll eat more proteins and fat which, in large quantities, can be detrimental to health (increased bad cholesterol, constipation, weight gain, …).
- Because ketones in large quantities can be harmful causing acidity in the blood, malfunctioning of the brain
How much carbohydrate do we need a day?
This again varies greatly depending on your activity level (from 0.9 to 1.4g per kg of your weight or 2/3g/lb).
Vitamins and Minerals
They’re called micro-nutrients because they appear in far lesser quantities than macro-elements in the food we eat but they are essential to good health. Each vitamin and mineral has a specific role to play in our body. We need a varied source of food to obtain them all.
They are not to be left out. Fibres are not nutrients per-se but they contribute to the good functioning of our body. Insoluble fibres (found in whole grain, bran, nuts, seeds, fruit skins,…) help with the good transit and elimination of food matter.
Soluble fibres (found in oats, barley, berries, apples,…) help regulate blood sugar and blood cholesterol.
We need 25 to 38g of fibres a day.
CONCLUSION… There is not ONE ideal food
The ideal food would need to contain the right proportion of carbs, healthy fats (including essential fatty acids), proteins (including essential amino acids), fibres and all the vitamins and minerals. Try as you may, that single super nutritionally balanced food does not exist.
Boring as it may be, there is some reason in the recommendation of a varied and balanced diet and that is to give the body as many of the nutrients as it needs in the right quantities in order to remain healthy.
If you want to limit the foods you eat, why not remove the manufactured, transformed, man-made ones (cakes, biscuits, candies, margerine, edulcorants, already made…)?
My advice… Go for natural, varied ingredients in moderate quantities. Learn to love making tasty food and enjoy eating it!