Narrator: Imagine a doctor telling a patient with type 2 diabetes that the key to reversing their condition is to lose weight. In the very next breath, that same doctor prescribes a medication, insulin, that is known to cause significant weight gain. This isn't a hypothetical scenario; it's a daily contradiction playing out in clinics worldwide. It highlights a profound and dangerous misunderstanding of a disease that affects hundreds of millions of people. How can the standard treatment for a disease actively worsen its underlying cause?

This paradox is the central mystery unraveled in Dr. Jason Fung's groundbreaking book, The Diabetes Code. He argues that the conventional approach to type 2 diabetes is fundamentally flawed because it focuses on the wrong problem. The book presents a new paradigm, reframing diabetes not as a chronic, progressive disease of high blood sugar, but as a reversible dietary disease of excess insulin.

Narrator: For decades, the medical community has treated type 1 and type 2 diabetes with a similar tool: insulin. This makes perfect sense for type 1, an autoimmune disease where the body destroys its own insulin-producing cells. But Dr. Fung argues this approach is disastrous for type 2 diabetes.

Type 2 diabetes is not a disease of too little insulin; it's a disease of too much insulin. The body has become resistant to insulin's effects. To understand this, Fung uses a powerful analogy of an overstuffed suitcase. Imagine your body's cells are a suitcase. For years, you've been packing them full of glucose (sugar). At first, it's easy. But eventually, the suitcase is completely full. To get more in, you have to push harder and harder. This "push" is insulin. The body produces more and more insulin to cram glucose into already overflowing cells. This state of high insulin is called hyperinsulinemia, and the cells' refusal to accept more glucose is insulin resistance.

Conventional treatments, like prescribing more insulin, are like getting a bigger person to help you shove more clothes into the already-bursting suitcase. It might get the clothes off the floor (lowering blood sugar), but it makes the underlying problem—the overstuffed suitcase—even worse. This is why patients on insulin often gain weight and find their condition progresses, requiring ever-higher doses. The problem isn't a lack of insulin; it's that the body is overflowing with sugar.

Narrator: If insulin resistance is the problem, what causes it? Dr. Fung pinpoints the cause not in the fat under our skin, but in the fat accumulating inside our organs, particularly the liver. He calls this the "overflow phenomenon."

When we consume excess carbohydrates and sugar, especially fructose, the body converts them into fat in the liver through a process called de novo lipogenesis. At first, the liver can export this fat to be stored in fat cells around the body. But when this system is overwhelmed, fat begins to build up inside the liver itself, creating a condition known as non-alcoholic fatty liver disease (NAFLD). A fatty liver becomes resistant to insulin's signals. It continues to pump out glucose even when blood sugar is already high, worsening the problem.

This overflow doesn't stop at the liver. Fat also begins to infiltrate the pancreas, clogging the very beta cells that produce insulin. This leads to beta cell dysfunction, where the pancreas can no longer produce enough insulin to overcome the body's profound resistance. This is the point where prediabetes often tips over into full-blown type 2 diabetes. The story of bariatric surgery provides stunning proof. Studies show that after surgery, patients can reverse their diabetes in mere weeks. It's not because the surgery is magical, but because the enforced severe caloric restriction forces the body to burn off the fat clogging the liver and pancreas, restoring their normal function.

Narrator: While all refined carbohydrates contribute to the problem, Dr. Fung identifies one sugar as a primary villain: fructose. Unlike glucose, which can be used by almost every cell in the body, fructose is metabolized almost exclusively by the liver.

This metabolic pathway makes fructose particularly effective at creating fatty liver. Dr. Fung compares it to the process of making foie gras, where ducks are force-fed corn (which is high in fructose) to deliberately induce a fatty, enlarged liver. Humans are essentially doing the same thing to themselves. The massive increase in consumption of sugar and high-fructose corn syrup since the 1980s directly parallels the explosion of obesity and type 2 diabetes.

The book highlights a paradox in global health trends. In countries like Sri Lanka, obesity rates barely rose, but diabetes rates skyrocketed, corresponding with a massive increase in sugar consumption. Meanwhile, in New Zealand, obesity increased, but diabetes rates fell as sugar intake was reduced. This shows that while obesity is linked to diabetes, sugar consumption, and specifically fructose, is a more direct and powerful driver of the insulin resistance that causes the disease.

Narrator: The book systematically dismantles the standard advice given to diabetic patients. The recommendation to "eat less and move more" through a low-fat, low-calorie diet is shown to be a catastrophic failure. The massive, multi-million dollar LookAHEAD trial, which put over 5,000 diabetic patients on this exact regimen, was stopped early because it showed absolutely no benefit in reducing heart attacks or strokes. This is because low-fat diets are often high-carbohydrate diets, which directly increase the glucose and insulin that are at the heart of the disease.

Similarly, exercise, while beneficial for overall health, cannot solve the core problem. As Dr. Fung states, "you cannot exercise your liver to health." Exercise can improve insulin sensitivity in muscles, but it cannot burn off the internal fat in the liver and pancreas quickly enough to reverse the disease on its own.

Finally, oral medications are critiqued for the same reason as insulin. Most of them, like sulfonylureas, work by forcing the pancreas to secrete even more insulin, which worsens the underlying hyperinsulinemia. They trade the problem of high blood sugar (glucotoxicity) for the problem of high insulin (insulin toxicity), without ever solving the disease.

Narrator: If type 2 diabetes is a disease of too much sugar in the body, the solution becomes remarkably simple, though not necessarily easy. It requires a two-step approach.

First, stop putting more sugar in. This means adopting a low-carbohydrate, healthy-fat diet. By drastically reducing the intake of sugars and refined carbohydrates like bread, pasta, and rice, the body is no longer forced to produce high levels of insulin. This addresses the dietary root cause of the disease. The book shares the story of Betsy, a medical researcher diagnosed with severe type 2 diabetes. Rejecting medication, she adopted a very low-carbohydrate ketogenic diet. Three months later, her blood markers had returned to the non-diabetic range, without any drugs at all.

Second, burn the stored sugar off. The most effective way to do this is through intermittent fasting. Fasting provides the body with the time it needs to switch from burning glucose to burning stored body fat, including the fat in the liver. This directly attacks the overflow problem, reducing fatty liver and restoring insulin sensitivity. Unlike constant calorie restriction which can lower metabolism, intermittent fasting maintains metabolic rate while effectively clearing out the body's excess sugar stores.

Narrator: The single most powerful takeaway from The Diabetes Code is that type 2 diabetes is not the chronic, progressive, and irreversible life sentence it is often made out to be. It is a dietary disease caused by hormonal imbalance, and because it is a dietary disease, it has a dietary cure. The solution is not found in a pill or an injection, but in understanding the true nature of the illness: an overflow of sugar in the body.

Dr. Fung's work challenges us to question the very foundations of conventional medical advice and to recognize that our bodies have a profound capacity to heal. The ultimate question it leaves us with is not whether we can reverse type 2 diabetes, but whether we have the courage to ignore the failed guidelines of the past and embrace a new understanding that puts the power of recovery back into our own hands.