This is Your Body on Sugar – Redux!

One of the great (and often times frustrating) things about science is that we continue to make discoveries that change the way we look at the scientific world as we know it. Each day, scientists uncover new knowledge, leading closer and closer to understanding how our bodies actually work.

It also forces us to question all our beliefs about the body, to be constantly open minded to new information.

In medical school we were told on our first day that within 10 years, more than 50% of what we learned during our 4th year would be disproven or out of date.

Think about that for a second. That’s an insane amount of information that today we think is “correct” but really isn’t.

Instead of acting like we know everything about health and medicine, we as health care practitioners need to be open to new ideas, theories, and evidence, while also being critical of the science that comes out (not all scientific studies are equal, unfortunately).

This means we’ve got a hugely complicated world to live in, all the while trying to do as well as possible for our health and that of our patients. It also means that we have to be willing to change the way we think based off new knowledge and information.

Why all this talk about new science? Its because after seeing some new science, I have to revise some stuff I talked about a few weeks ago.

I want to take you back to a recent article we posted regarding sugar’s effect on the body. Look at the graphic shown below.


In that article, I talked about the role of glucose and insulin spikes and their effects on hunger, satiety (feeling full), and energy. In particular, I talked about how these rapid spikes lead to reactive hypoglycemia, hunger, and the classic “hangry” symptoms.

It appears, having looked at new research, that the human body is actually a bit more complicated…who would have thought right?

A recent study looked at the effects of blood glucose levels on hunger and satiety. To summarize, they took healthy young men and infused large amounts of glucose solution intravenously and monitored their blood glucose levels along with feelings of hunger and satiety. They compared this to men who did not receive the infusion. Note: no food was involved.

As you can probably imagine, those who received the glucose infusion showed a spike in their blood glucose and insulin levels, eventually leading to a drop in blood glucose similar to the drop seen in the figure above (red solid line). Those who had not received the glucose solution had relatively stable/normal blood glucose levels.

What is interesting about this study is that even though the experimental group (those who had the glucose infusion) ended up with lower blood glucose levels, there was no difference in feelings of hunger between the 2 groups (after 1 hour – kind of a short follow up period, in my opinion).

The conclusion here is that hypoglycemia (low blood glucose level) by itself does not result in hunger.

I actually tested and confirmed this finding on myself. I monitored my blood glucose levels with a glucometer following meals, and specifically when I feel hungry. Generally, when I’m feeling hungry (or hangry), my blood glucose levels are not in that “hypoglycemia” range.

In my previous article, I pointed to hypoglycemia as a cause of hunger. It appears I have been proven wrong. I have steered you awry and I am sorry!

But there is still a lot of other stuff involved too.

Basically, what this study tells us is that hypoglycemia (by itself without any relation to food) does not cause hunger. But this is an artificial condition. Most people do not go around infusing glucose solutions into their veins on a normal daily basis.

What this study really shows is that there are a lot of factors that play a role in how we feel following a meal. Though isolated hypoglycemia does not cause hunger, other body mechanisms that occur following a sugary meal likely do. These could include digestion time (see our last article here), fructose (a sugar that has no effect on blood glucose levels, but many bad effects on the body), and probably many other factors. The thing is, we don’t know yet.

The point is we don’t really know what exactly causes someone to feel hungry (or hangry) following a sugary meal. But we do know that it happens. You can try it yourself, see how you feel a couple hours after a sugary meal. The holidays would be a perfect time to try it!

Note: Yes I did just say you can eat a sugary meal. You only live once, right? Gotta enjoy it sometimes, especially with pies and cookies coming for the holiday season. Just don’t go overboard. If you’re a nerd like me, you can use it as a time to self experiment (glucometers are pretty cheap and easy to use)!

The Takeaway

In the end, we do know this: sugary meals cause glucose and insulin spikes, along with frequent hunger/overeating, insulin resistance, obesity, and other health issues.

It is not necessarily the hypoglycemia that causes you to feel hungry a few hours later. More likely, its a combination of multiple factors.

Even though the mechanism is more complicated than we’d probably like, these effects do happen. That means its still important to understand the dangers of sugar. As science continues forward, we’ll learn more and more. So stay tuned, and enjoy the holidays.

About the Author

Chris Goodrich, MD

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