The emerging research on the role of fructose as a survival signal for fat storage gives another reason why people can’t lose body fat or keep gaining it no matter what they do. 

It shows a secondary mechanism that can cause insulin resistance without our fat-storage hormone insulin.

This compelling evidence has challenged my point of view and understanding of insulin resistance, weight gain, and loss, and how metabolic dysfunction shows up in our society.

The body continually makes fructose and monitors its amount and what we eat very closely, setting off a survival alarm when levels rise even slightly. 

When the fructose alarm goes off, it switches our energy production, lowering cellular energy by 20% to 60% by changing how and where we make our energy. 

The other side of that alarm response creates insulin resistance, promotes the formation of liver fat, and causes fat storage at a very alarming rate, independent of how many calories we consume. 

The more fructose someone consumes semi-regularly, the more adapted we become to that switch turning on and staying on. 

It mirrors the process of becoming fat-adapted that people go through when eating a low-carb, keto, carnivore, or insulin-friendly eating style.

Like most people, I have eaten more than my fructose limit as a child, in college, and even recently. I am fructose adapted, or at one point, I was for a very long time, if not for my entire life, which explains a lot. 

Being fructose-adapted means my system is primed and highly sensitive to these mechanisms responding to fructose. 

Suppose I want to break that hyper-reaction in my system and attempt to recover metabolically from this. In that case, it will take significant work—more work and vigilance than I have ever enlisted for my diet. And I have held a pretty high nutritional standard for much of my life, so that says a lot.

What makes this process so daunting is that this switch is turned on by other alarms besides eating fructose. 

Other alarm triggers for this survival response are high glucose levels, mild dehydration, low oxygen levels, high uric acid levels lower than the medical reference range of  7.0 mg/dl in males and 6.0 mg/dl in females, and a high sodium concentration in the blood. 

The natural dietary limit is about 6 grams of fructose from non-liquid sources and is set by the gut’s ability to metabolize it before it gets to the liver, where the alarm sensors are. 

To put the 6-gram threshold into context, an apple has 5.9 grams, a banana has 4.9, oranges 2.25, a carrot has .6, sweet onions have 2, grapes have 8.1, and dried figs have 22.9 grams. 

Fructose at even lower levels, when consumed in liquid form, will trigger the alarm quicker than anything else due to the quick absorption and consequent increase in fructose concentrations in the liver and blood. The rapid change in the blood concentration triggers the alarm as much, if not more, than the total amount. The same is true with salt concentrations. 

These fructose pathways change the landscape in my world significantly. Although the explanation is different, the fortunate silver lining for me is my insulin-centric lens regarding metabolic health, and programs also address this alternate model. 

More research will need to be done to confirm these mechanisms in humans, but understanding that these mechanisms are very well understood in animals. As a core genetic response found in all animals, it doesn’t provide much room for the argument that we are all that different. 

It’s more evidence to use and new thinking to develop that can only offer better options and new strategies for reversing the metabolic dysfunction that is killing the modern world.

This is a very big and complicated concept that is riddled with individual variables to sort through. 

As I do, I will share what I learn and make evident any changes in the approach or application of how I live and practice as well as teach. 

New information can be disruptive. Being open to disrupting what we believe is true and growing as we do things differently has always been the ultimate goal.

Here’s to another rabbit hole, my friends!

We can do better!

Dr. Don