Brain needs glucose.
But that glucose is made by your body from the food that you eat, at a steady pace.
But if you eat sugary food, it will increase your blood sugar level too fast. Causing your body to produce lots of insulin. The insulin's job is to get the sugar out of your blood to restore safe sugar levels. The two ways in which insulin does this is:
- Using the sugar for muscle cells that are active and need fuel.
- If there are no muscle cells needing fuel, then it gets stored as glycogen in fat cells for later use, when blood sugar levels are too low.
So even though almost all of your body needs glucose, it's not the best if you eat that directly. Unless you would consume the glucose in a constant way keeping your blood sugar level constant. That could be done with an IV, but our bodies have this mechanism that they can take high- protein/fat & low- sugar/carb contents food and use that as a constant source for several hours. Then you only need to refill the stomach once in a while instead of being connected to an IV all day.
Edit: BTW, when the blood sugar level spikes from sugary food, insulin will spike thereafter, causing the sugar level to drop very fast, eventually making you feel tired and hungry, craving for a quick (sugary) snack, and the cycle starts again.
An example of this is Oral Rehydration Solution (ORS). Many people around the world suffer from dehydration, and electrolyte solutions are more effective when combined with glucose in a liquid form. Interestingly, the study often cited to argue that non-glucose-based versions are equally effective is misleading. In that study, participants consumed orange juice and cereal bars one hour before the test, which influenced the results. https://www.frontiersin.org/journals/sports-and-active-livin...
The liver and muscles act as natural buffers, storing excess glucose as glycogen and releasing it as needed, so a small sugar spike here and there—like a few pieces of candy—won’t typically lead to insulin resistance or other long-term problems. Issues like insulin resistance are more of a concern with constant, high sugar intake over time, particularly if the overall diet lacks fiber and nutrients and particularly for people who are inactive.
So, while excessive sugar intake isn’t great, enjoying sugar in moderation doesn’t overwhelm the body’s ability to regulate blood sugar. Our metabolic systems are designed to manage occasional spikes, and a balanced approach is key.
Every 10 years, the dietician community tends to demonize one type of macronutrient. When a theory claims that a single factor explains a complex phenomenon, it’s usually a red flag that the theory is flawed.
So yeah in moderation everything is ok of course, but I do have the feeling that on average, we might be overdoing it a little bit with the sugar.
I’m very interested to see ubiquitous continuous glucose monitors in action and the data we will get from that.
The high degree to which GLP-1 medicines work aide in your argument RE insulin quite a bit. I am just very suspect of all the keto claims (not made by you - just in general). If keto was a panacea then in the last 40 years we would have seen a bigger dent in obesity.
I think it is actually largely a psychological story. Food is like an addiction, a way of distracting yourself from the struggles of life. And addictive food (candy, snacks, fast food) is just the kind of drug that is easiest available to most people, and it's not illegal or necessarily looked down upon, even promoted in many ways (birthday cake). So that is why it's one of the bigger problems in society.
And the solution for addictions is not taking away the drug, because the desire is still there, and will eventually sip through in some other way. The way to deal with it is to look into the root cause of what is lacking in the life of the user causing it to try to fill up this hole in it's life with this drug. And then have a proper way of treating that, while also learning more about nutrition, because people have also just forgotten what healthy food is and how to make it.
Before modernity, maintaining long-term ketosis (eg decade+ length) would have been extremely difficult. Some anti-sugar advocates portray sugar as inherently evil, suggesting that any consumption will lead to significant harm.
However, moderation is often more practical:
1. Many marathon runners use glucose gels and still enjoy long, healthy lives, typically living about 7 years longer than non-athletes.
2. Most researchers at the National Institute on Aging do not recommend avoiding all sugar or focusing solely on ketogenic diets. In fact, studies show that intermittent fasting often leads to longer lifespans than ketogenic diets.
3. New data is showing that long term ketogenic diets lead to the death of healthy cells, increased adipose tissue, increased triglycerides https://www.science.org/doi/10.1126/sciadv.ado1463