Isn't it unhealthy to not eat carbs?
By The Low Carb Clinic, 23 April 2019 - 759 words (4 minutes)
It goes without saying that good nutrition promotes better health outcomes. Most guidelines recommend that in order to be healthy, we should eat a diet that is high in carbohydrate, moderate in protein and low in fat. But did you know that, while there are essential dietary fats and proteins, there is no essential carbohydrate? Is eating a diet that is majority carbohydrates really making us healthy?
There are many nutrients that are essential for human life. ‘Essential’ nutrients cannot be made by the human body – we must get them from our diet. If we don’t get them from our diet, we won’t develop, grow and thrive as we should – and we have an increased risk of a huge range of diseases, and early death.
There are three macronutrients: carbohydrates, fat and protein. Most dietary guidelines recommend that we eat about 45-65% carbohydrate, 20-35% protein, and around 10-30% fat.
These guidelines are, in part, based on the commonly held belief that the human body needs to consume at least 100-120 grams of carbohydrate per day – but unfortunately, this is simply not true.[1]
There are certain proteins that are essential.
There are 9 essential amino acids (protein building blocks). Foods that are ‘complete proteins’ contain all nine of these amino acids. Most complete proteins are animal foods, like meat, fish, poultry, eggs, and dairy. While there are a few plant sources like quinoa that can supply all 9 amino acids, these sources contain protein in much lower concentration, and are more poorly absorbed, therefore limiting our access to them. These plant sources also ‘package’ the small amount of protein with a lot of carbohydrates in the same mouthful.
There are certain fats that are essential.
There are 2 essential fatty acids – omega-3 and omega-6. Many animal products contain both omega-3 and omega-6 (like grass-fed beef, fish and shellfish). While there are also some non-animal sources, like flaxseeds and walnuts, these sources contain omega 3’s that our bodies’ can’t use (ALA, as opposed to the DHA that we need). We therefore get a much bigger dose of essential fatty acids eating animal sources.
There are certain vitamins and minerals that are essential.
Different vitamins and minerals are found in different foods – that’s why it’s important to enjoy variety in your diet. For example, vitamin A is found in high amounts in liver and eggs, calcium in cheese and leafy greens, and vitamin B5 in avocados.
But there is no essential carbohydrate.
Carbohydrates are broken down into glucose, and it is true that the body needs a little bit of glucose every day – about 20-30 grams, used in places like red blood cells or in the brain.
But the reason why carbohydrates are not essential is because our body can make all the glucose it needs from fat and protein, in a process called gluconeogenesis.
And when we don’t eat carbohydrates for energy, our liver simply makes ketones from fat instead. Research shows that using ketones for fuel is actually cleaner and more efficient than using glucose - ketones produce less oxidative stress [2], less inflammation, and more energy than glucose does! [3]
So, no, we don’t need to eat carbohydrates to be healthy.
Carbohydrates are commonly divided into two types: simple carbohydrates, and complex carbohydrates.
Simple carbohydrates are sugars – smaller molecules containing glucose. Simple carbohydrates are found in obvious places like sweets and desserts, but also in fruit, vegetables, honey and milk. Complex carbohydrates are longer molecules of glucose called starch. Starch is found in bread, pasta, rice and potatoes. In the body, both types of carbohydrates are broken down into glucose.
This isn’t to say that all carbohydrates are bad – whole food sources of carbohydrates, like vegetables, offer fibre (a non-digestible form of carbohydrate), which offers a range of benefits to our health. Fibre is absorbed very differently from other types of carbohydrate – to be more precise, fibre isn’t actually absorbed by the human body at all – fibre is digested by our gut microbiome: the bacteria living in our gut. Fibre feeds our gut bacteria and can promote better blood sugar regulation[4], improved immunity[5], and lower levels of inflammation[6]. But you can get plenty of fibre on a low carbohydrate diet, from a range of vegetables (leafy greens, cabbage, cauliflower), nuts and seeds, and avocado. There’s simply no need for breads, pastas, rice or cereals.
Carbohydrates are not nourishing out bodies, so why eat them? By prioritising low-carbohydrate, nutrient dense whole foods – rich in essential proteins and fats – we offer our body the best chance at success.
Food for thought?
References
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[1] Manninen, A. (2004). Metabolic effects of the very-low-carbohydrate diets: misunderstood "villains" of human metabolism. Jounral of the International Society of Sports Nutrition, 1(2), 7-11. doi:10.1186/1550-2783-1-2-7
[2] Mattson, M., Longo, V., & Harvie, M. (2017, October). Impact of intermittent fasting on health and disease processes. Ageing Research Reviews, 39, 46-58. doi:http://dx.doi.org/10.1016/j.arr.2016.10.005
[3] Johnstone, A. (2005). Fasting - the ultimate diet? Obesity reviews, 8, 211-222. doi:doi: 10.1111/j.1467-789X.2006.00266.x
[4] Rajoka, M., Shi, J., Mehwish, H., Zhu, J., Li, Q., Shao, D., . . . Yang, H. (2017). Interaction between diet composition and gut microbiota and its impact on gastrointestinal tract health. Food Science and Human Wellness, 6, 121-130. doi:http://dx.doi.org/10.1016/j.fshw.2017.07.003
[5] Wang, B., Yao, M., Lv, L., Ling, Z., & Li, L. (2017). The human microbiota in health and disease. Engineering, 3, 71-82. doi:http://dx.doi.org/10.1016/J.ENG.2017.01.008
[6] Sonnenberg, E. (2018, Jan 10). Understanding the microbiome. Retrieved from Youtube: https://www.youtube.com/watch?v=miEngVBrrIc