Episode Details

Type 2 Diabetes, Bariatric Surgery, Fasting, and GLP-1s: What We Finally Learned About a Disease We Thought We Understood

For years, I watched something happen in bariatric surgery that made very little sense, according to the medical textbooks of the time.

Patients with type 2 diabetes would undergo surgery, and within days, their blood sugars would improve dramatically. Some would leave needing far less insulin. Others would stop insulin entirely. Many of them would eventually remain off diabetes medications for years.

Now here is the important part:

They had not yet lost significant weight.

That observation mattered enormously.

Because if diabetes improvement were simply the result of fat disappearing from the body over time, then blood sugar should improve slowly over months as weight comes off.

But that was not what we saw.

Instead, patients barely eating — sipping broth and protein shakes while recovering from surgery — were suddenly metabolically different almost immediately.

At the time, we knew it worked. What we did not fully understand was why.

And honestly, that story tells you something important about medicine and science: sometimes clinical medicine notices the truth before biology fully explains it.

For decades, type 2 diabetes was often taught in very mechanical terms. You gained weight. You became insulin-resistant. The pancreas worked harder and harder until it “burned out.” Then you needed insulin.

That explanation was not entirely wrong. However, it was incomplete. Furthermore, it encouraged a kind of fatalism around type 2 diabetes, as though progression were inevitable and irreversible for everyone.

Then, bariatric surgery complicated the narrative.

Meanwhile, researchers like Professor Roy Taylor at Newcastle University began developing a much more dynamic understanding of what was actually happening inside the liver and pancreas.

And suddenly, many of the strange things bariatric surgeons had observed for years started making sense.

The Problem May Not Be Sugar Alone

One of the most common mistakes in nutrition discourse is assuming that blood sugar itself is the disease.

It is not.

Blood sugar is often the visible signal of a much larger metabolic problem involving:

• the liver,
• the pancreas,
• adipose tissue,
• appetite signaling,
• inflammation,
• gut hormones,
• and the brain itself.

Now, to be fair, refined carbohydrates and ultra-processed foods absolutely can worsen insulin resistance and glucose control. Sugary beverages, highly refined starches, and hyperpalatable processed foods create enormous metabolic stress for many people.

However, reducing the entire disease of type 2 diabetes to “sugar is poison” oversimplifies what is actually a highly complex biological system.

If carbohydrates alone caused diabetes, then traditional Mediterranean populations consuming beans, lentils, intact grains, and fruit would have universally developed severe metabolic disease. Yet many of those populations historically had some of the best cardiovascular and metabolic outcomes in the world.

Similarly, bariatric surgery would not improve diabetes before substantial fat loss occurred.

Something deeper was happening.

Roy Taylor and the Twin Cycle Hypothesis

Roy Taylor’s Twin Cycle Hypothesis is one of the most elegant modern explanations for type 2 diabetes.

The theory proposes that type 2 diabetes develops through two interconnected metabolic cycles, involving excess fat accumulation in organs not designed to store large amounts of fat.

First comes the liver. When caloric intake chronically exceeds what the body can safely store in adipose tissue, fat begin