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Carbohydrates are one of the three main macronutrients our body needs. The internet is flooded with contradicting ‘opinions‘ on carbohydrates, however the truth is – they are pretty important for the human body. Carbohydrates are a major food source and a key energy source for the human body.
Carbohydrates are not classed as an essential nutrient for us humans, this means that we do not need it to survive. We can get all of our energy from protein and fats if needed (however that causes other problems). However, the biggest problem lies in the fact that our brain requires carbohydrates – roughly 50g of glucose is required daily just to keep the brain functioning properly. Carbohydrates also play an important role in bowel movement regulation, maintain hormone balance, stimulating immune system function, antioxidant production, protein sparing and very importantly the supply of fibre.
Carbohydrates are arguably one of the main causes of obesity and diabetes in developed countries. There is big support for that, however, it results in an inaccurate representation of carbohydrates as the ‘big bad thing’ in nutrition. This although true to some aspects is not entirely true. In Australia there is no RDI in terms of carbohydrate consumption, it is estimated that the average Aussie will consume 45-65% of their total energy in the form of carbs. Taking a 2000kcal diet into account, that will result in roughly 900-1300kcal of carbohydrate intake equating to roughly 225g-325g of carbohydrates which in personal opinion is far too much especially as the majority of the intake comes in the form of high GI processed carbs from fast food/junk food. Personal opinion aside, in terms of carbohydrate intake, the Australian NRV states that the type of carbohydrate consumed is directed related to the health outcome and various roles carbohydrates play in chronic disease.
In our current society and lifestyle, carbohydrates are far too easy to consume. At a bare minimum stick to 50g of carbs a day to at least allow your brain to function properly without the dreaded ‘grey brain or brain fuzz’. From there, it is completely up to you and your current health and fitness goals to establish a carbohydrate goal or guideline for you to follow. This is mostly dictated by what sort of diet or health goal you are following. For example, a keto diet technically calls for <50g of carbs a day, however we won’t discuss various diets today and keep it for next time.
Health authorities generally recommend 40-65% of daily caloric intake to be sourced from carbohydrates with only 10% being ‘simple’ carbs.
Okay, let’s talk about what carbohydrates do in the human body. Once chewed up and swallowed, carbohydrates will be broken down by the digestive system into the smallest functional molecule of glucose. This glucose molecule will enter the blood stream resulting in the rise of blood glucose levels, this triggers the release of insulin by beta cells in the pancreas (Please drop a comment below if I’m getting too scientific for you). This hormone, insulin is extremely important. It is a hormone that allows our cells to absorb the blood glucose for energy use or storage. When blood sugar levels get low, the alpha cells of our pancreas release a hormone called glucagon which triggers the release of glycogen (stored form of glucose) from the liver to bring blood glucose back to a normal level. So you can see now that carbs cause fluctuations in blood sugar levels which causes the pancreas to work hard to fix it. If blood glucose levels fluctuate rapidly and too often, cells can eventually develop problems which result in decreased glucose uptake. Simply put, this leads to higher production of insulin by beta cells, which wears them out in the long term and causes damage, eventually leading to reduced insulin production and constantly high levels of blood glucose (this is known as insulin resistance – an A1C score of 5.7-6.4% or fasting blood glucose levels of 100-125mg/dL).
Insulin resistance results in hypertension (high blood pressure), high blood triglycerides, low levels of HDL (good cholesterol), weight gain, and a plethora of chronic diseases – This is known as metabolic syndromes which results in the end game of Type 2 Diabetes (How many people do you know with diabetes?)
So how can you minimise your disease risk chance? The answer is in the type of food we eat.
Carbohydrates which come from natural and unprocessed foods such as fruits, legumes, whole grains and some cereals usually contain essential vitamins, minerals, fibre, and phytonutrients. However, carbohydrates sources from processed foods are usually high in sugars and hold low to none nutrient content (Another reason to still eat carbs but it natural low GI forms).
Forms of carbohydrates (IMPORTANT to consider for food selection):
- Low G.I vs High G.I
- ‘Simple’ vs ‘Complex’
- Sugars vs starches
G.I is amazing, Sydney Uni has played a huge role in the development of the G.I (glycemic index) system of classifying carbohydrates. More in-depth detail will be discussed in the Glycemic Index blog post.
In regards to the above, it’s really all the same. Just different common names for the same thing. I prefer the G.I system because I come out of USYD and also because it is a very easy visual representation of carbohydrate quality.
So… Simple carbs are really just sugars, chains of 1-2 saccharides (scientifically known as mono or di-saccharides) and simple carbs are broken down quickly due to their simple structure which also makes them high G.I (the higher the G.I the faster it enters your blood).
And… Complex carbs are really just starches, chains of up to 10 or more saccharides (oligo or poly-saccharides in scientific speak) and complex carbs are broken fairly slowly in comparison to their simple counterparts because of their form which makes them low G.I which results in a smaller fluctuation of blood sugar levels which means that they are technically ‘healthier’ for you.
One last thing – Fibre.. It’s technically a carb but we’ll go into more detail on it’s own blog post of Nutribet! Stay tuned.
Let me help you with a list:
Simple/High G.I/Sugars (Avoid or eat very little of):
- Refined sugar
- Dairy sugars (galactose/lactose)
- Refined flour
- Soft drinks, chocolate bars, confectionary, most junk food..
Complex/Low G.I/Starches (Eat them!!):
OH… Excess carbohydrate intake which is not utilised becomes fat. So complex macronutrient manipulation will utilise both forms of carbs to help you achieve the best results with minimal fat gain.
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