I recently discovered a two part article written by Cyrus Khambatta, PhD which is the most well written summary explanation of carbohydrate metabolism I’ve ever read. It speaks to how low carb causes rapid weight loss – and the potential risks of long term low carb, high protein/fat intake.
The brain needs a constant source of glucose for energy which it can’t get from proteins and fats. Complex carbs provide that. The brain is the only organ that relies exclusively on glucose. It can’t store glucose. It has to get it from the liver from the storage form called glycogen. If the liver runs out of glycogen from low carb intake the brain doesn’t get enough glucose. As he notes, we can only store enough glucose for about 24 hours of brain activity before we run out of liver stored glycogen.
I get completely now how paleo and the Keto diet cause rapid weight loss. But the lack of healthy carbs for brain function may have negative effects long term. If you read the articles note that he makes one type o by stating a high glucose to fructose intake ratio is preferable. (He meant the opposite). In short the best carbs are natural whole fruits and vegetables and the worst are refined grains/rice and all refined sugars.
Long term the lack of healthy carbs also causes resistance to the effect of insulin on muscle – which leads to insulin resistance and potentially diabetes.
Relatedly, the intake of unhealthy carbs causes inflammation/oxidation, adipose storage, cell degeneration and multiple diseases, like heart and brain degeneration and also diabetes, as oxidation contributes to muscle cell insulin resistance.
It’s not news but it’s a good reminder – people are best to get carbs from fruit and starchy veggies as opposed to refined cereals/pasta and juices/deserts/sugary drinks and foods. So after the chips, tortillas, beer, wine and flan I ate last night…my yuk feeling now and weird hunger makes sense – it’s dis-regulated carbohydrate metabolism. I never feel this way when I eat an apple.