1장
The Silent Epidemic: Unmasking the Truth About Diabetes
Imagine waking up one day to discover that a disease once considered rare has become a global epidemic affecting nearly half a billion people worldwide. Type 2 diabetes, once an obscure condition primarily affecting the elderly, now strikes children as young as three. This metabolic disorder has transformed from medical curiosity to public health crisis in just one generation, yet conventional medical wisdom continues to label it "chronic and progressive" - a life sentence of deteriorating health and increasing medication.
Dr. Jason Fung's groundbreaking book challenges this fatalistic view with a revolutionary premise: type 2 diabetes is fully reversible through dietary changes rather than medications. This isn't just theoretical - his approach has enabled countless patients to eliminate insulin injections after decades of dependency. The book has become a cultural phenomenon, endorsed by health professionals worldwide and sparking a movement that questions the pharmaceutical-centered approach to diabetes management. What makes Fung's work particularly compelling is that his solution isn't new or experimental - it's rooted in treatments that predate insulin therapy but were forgotten when medication became the standard of care.
2장
Diabetes: From Rare Disease to Global Pandemic
For thousands of years, diabetes was recognized across ancient civilizations. Egyptian texts from 1550 BC described "passing too much urine," while Hindu writings discussed "honey urine." Greek physician Aretaeus of Cappadocia provided the most vivid description, calling it "the melting down of flesh and limbs into urine," noting that "life with diabetes is short, disgusting and painful."
The first effective treatment came in 1797 when John Rollo developed an all-meat, extremely low-carbohydrate diet that showed substantial improvement in diabetic patients. By contrast, Pierre Piorry's contradictory advice to consume more sugar proved fatal. By 1910, Sir Edward Sharpey-Schafer proposed that insulin deficiency caused diabetes, leading physicians Frederick Allen and Elliott Joslin to become strong proponents of intensive dietary management.
Everything changed in 1921 when Frederick Banting, Charles Best, and John Macleod discovered insulin at the University of Toronto. After purifying insulin from cow pancreases, they administered it to fourteen-year-old Leonard Thompson, who immediately regained normal weight and saw his symptoms disappear. The average lifespan of young diabetics increased from sixteen months to thirty-five years. This breakthrough overshadowed previous dietary treatments, but soon revealed that different types of diabetes existed.
The roots of today's epidemic trace back to the 1950s when dietary fat was falsely vilified as the cause of heart disease. The 1977 "Dietary Goals for the United States" recommended increasing carbohydrate consumption to 55-60% of calories while decreasing fat to 30%. The infamous food pyramid placed breads, pastas and potatoes at its base as daily essentials - precisely the foods that provoke the greatest rise in blood glucose and insulin. Obesity rates increased immediately after these guidelines were implemented, and ten years later, diabetes began its inevitable rise.
Today, diabetes affects 422 million people worldwide, with 80% living in developing countries. China has become the diabetes epicenter with 11.6% of adults affected, a staggering 1160% increase since 1980. In the U.S., 14.3% of adults have type 2 diabetes and 38% have prediabetes - meaning for the first time in history, more Americans have the disease than not. With estimated costs of $245 billion annually and medical expenses 2-5 times higher than for non-diabetics, diabetes threatens to bankrupt entire healthcare systems.
3장
Understanding the Two Faces of Diabetes
Diabetes mellitus encompasses several disorders characterized by chronically elevated blood glucose. Type 1 diabetes results from an autoimmune destruction of insulin-producing cells, while type 2 diabetes (approximately 90% of cases) involves insulin resistance rather than insulin deficiency. Despite sharing the symptom of high blood glucose, these conditions are fundamentally opposites - one characterized by very low insulin levels, the other by very high ones.
In type 1 diabetes, the body's immune system destroys insulin-producing cells, evidenced by antibodies to islet cells in patients' blood. Despite insulin treatment, type 1 diabetics face higher complication risks, with life expectancy reduced by 5-8 years and heart disease risk increased tenfold.
Type 2 diabetes, historically affecting older adults, is rapidly increasing in children alongside obesity rates. Unlike type 1, type 2 features insulin resistance rather than insulin deficiency - surprisingly, insulin levels are high, not low. The body compensates for this resistance by increasing insulin secretion, but when this compensation fails to keep pace with increasing resistance, blood glucose rises.
Yet treatment paradigms for both primarily target blood glucose by increasing insulin, addressing only the symptom rather than the underlying disease. While insulin helps type 1 diabetes by replacing what's missing, it doesn't address the core problem of type 2 diabetes: insulin resistance. Without understanding the cause of this resistance, we can't hope to reverse the disease.
4장
The Devastating Toll: How Diabetes Destroys the Body
Diabetes uniquely devastates virtually every organ system. Its complications are classified as either microvascular (affecting small blood vessels in eyes, kidneys, and nerves) or macrovascular (affecting large blood vessels in the heart, brain, and legs).
Diabetes is the leading cause of blindness in the United States, with approximately 10,000 new cases annually. It weakens small retinal blood vessels, causing blood and fluids to leak. In response, new fragile vessels form that easily break, leading to more bleeding and scar tissue formation that can eventually detach the retina.
Diabetic kidney disease is the leading cause of end-stage renal disease, accounting for 44 percent of all new cases. When kidneys fail, toxins build up, causing loss of appetite, weight loss, persistent nausea and vomiting, and eventually coma and death if untreated. Patients with over 90 percent kidney function loss require dialysis indefinitely unless they receive a transplant.
Diabetic nerve damage affects 60-70 percent of diabetes patients. Symptoms include tingling, numbness, burning, and often debilitating pain that worsens at night and resists even powerful painkillers. The loss of protective pain sensation can lead to repeated trauma and joint destruction, potentially requiring amputation.
Diabetes dramatically increases the risk of atherosclerosis - the hardening and narrowing of arteries that leads to heart attacks, strokes, and peripheral vascular disease. It increases heart attack risk two- to fourfold, with complications developing at younger ages than in non-diabetics. Sixty-eight percent of diabetics aged 65+ die of heart disease and another 16 percent from stroke.
Beyond these complications, diabetes increases risk for most common cancers, is linked to Alzheimer's disease (sometimes called "type 3 diabetes"), causes non-alcoholic fatty liver disease in 75 percent of patients, increases susceptibility to infections, and is associated with numerous skin conditions and erectile dysfunction.
Despite centuries of knowledge about diabetes, complications are worsening, not improving. Our obsessive focus on lowering blood glucose addresses only the symptom, not the cause. Until we target the root cause - insulin resistance - the type 2 diabetes epidemic and its devastating complications will continue to worsen.
5장
Diabesity: The Insulin-Weight Connection
The term "diabesity" unifies type 2 diabetes and obesity, recognizing them as essentially the same disease. In 1990, Dr. Walter Willett identified the strong relationship between weight gain and type 2 diabetes, finding that gaining 44-77 pounds increased diabetes risk by 11,300 percent. Even slight weight gain significantly raises risk, while weight loss decreases it by over 50%.
However, the conventional "eat less, cut calories" advice has utterly failed to address obesity. The fundamental flaw in the calories-in/calories-out model is ignoring how the body adapts - when you reduce caloric intake by 40%, your basal metabolic rate drops by 40%, preventing weight loss. The Women's Health Initiative study devastatingly proved this: 50,000 women reduced calories for seven years with virtually no weight loss. The conventional approach has a 99.4% failure rate because it falsely assumes metabolic rate remains stable and that weight is consciously regulated.
In reality, body weight is hormonally controlled, just like all other vital bodily systems. Hormones, not willpower, control hunger and satiety. Ghrelin triggers hunger while cholecystokinin and peptide YY signal fullness. Obesity isn't about excess calories but about energy distribution - too much energy diverted to fat storage rather than other bodily functions.
Insulin is the master hormone of energy storage. When we eat, insulin rises, signaling the body to store energy as glycogen and fat. During fasting periods, insulin falls, prompting the body to break down glycogen for immediate energy and eventually burn fat. This balanced system maintains stable weight when feeding (high insulin) and fasting (low insulin) periods are balanced. However, when insulin remains persistently elevated, the body continuously receives signals to store fat, leading to weight gain.
The causal relationship between insulin and weight gain is clearly demonstrated in medical practice. Insulin prescriptions for diabetes invariably cause weight gain as a side effect. Insulinomas (rare tumors that secrete excessive insulin) cause persistent weight gain until surgically removed. Conversely, untreated type 1 diabetics with pathologically low insulin cannot gain weight regardless of caloric intake. These examples prove that obesity is fundamentally a hormonal imbalance, not a caloric one.
6장
The Overflow Phenomenon: How Insulin Resistance Develops
Obesity typically precedes type 2 diabetes by a decade or more, with fasting insulin levels progressively increasing through obesity to prediabetes to diabetes. However, hyperinsulinemia appears to be the underlying "X factor" causing both conditions.
Insulin resistance develops as a protective homeostatic mechanism against chronically elevated insulin levels. The body naturally resists change outside its comfort range by adapting to it - exposure creates resistance. This principle is illustrated by the case of Laura, who developed an insulinoma (insulin-secreting tumor) that caused excessive hunger, weight gain, and dangerous hypoglycemia. Her body protected itself by developing insulin resistance to shield against dangerously low blood glucose. When her tumor was removed, both the high insulin levels and the insulin resistance reversed, demonstrating that insulin itself causes insulin resistance.
Resistance is a fundamental biological principle across multiple domains. When exposed to constant stimuli, systems develop resistance - whether it's people tuning out persistent noise, bacteria evolving against antibiotics, or bodies building viral immunity through vaccines or natural exposure. The mechanism varies, but the principle remains consistent: exposure creates resistance, and removing the stimulus removes the resistance.
Studies prove this directly: healthy volunteers given constant insulin infusions for 40-96 hours developed 15-40% increased insulin resistance. The implications are staggering - I can make anyone insulin resistant simply by giving them enough insulin. In type 2 diabetics, higher insulin doses create greater insulin resistance, even as blood glucose improves.
The traditional lock-and-key paradigm of insulin resistance fails to explain a central paradox: insulin's action to stop glucose production is blunted, yet its action to create new fat is paradoxically enhanced. The overflow phenomenon resolves this paradox. Rather than the cell being starved of glucose, it's already overflowing with it. Like a packed subway train that can't accept more passengers despite open doors, glucose can't enter cells already jammed full. Hyperinsulinemia acts as a "subway pusher," forcibly shoving more glucose into stuffed cells. The overfilled cell produces excess fat to relieve internal glucose congestion, explaining fatty liver development and resolving the paradox.
7장
The Twin Cycles of Type 2 Diabetes
Type 2 diabetes represents two separate physiological defects: insulin resistance and beta cell dysfunction. These two prerequisites share the same underlying mechanism rather than occurring for separate reasons.
Insulin resistance emerges about thirteen years before type 2 diabetes develops. During this phase, compensatory hyperinsulinemia prevents rapid blood glucose elevation, though levels gradually rise. Visceral fat deposited around organs drives insulin resistance, with the liver being the first accumulation site. This creates a vicious cycle: hyperinsulinemia causes fatty liver, which causes insulin resistance, which leads to more hyperinsulinemia.
The connection between obesity and liver damage began emerging in the 1950s when Dr. Samuel Zelman observed fatty liver in a hospital aide who consumed twenty bottles of Coca-Cola daily. Fatty liver can develop in just three weeks through excessive sugar consumption. When glucose and insulin drive new fat production (DNL) faster than the liver can export it to fat cells, fat accumulates in the liver. Fortunately, when sugar consumption decreases, these changes completely reverse, with a mere 4% decrease in body weight reducing liver fat by 25%.
Skeletal muscles also become infiltrated with fat when hyperinsulinemia and excess sugar cause the liver to distribute triglycerides throughout the body. This intramyocyte lipid accumulation - essentially "fatty muscle" - resembles the marbling in premium beef. This fatty infiltration creates insulin resistance in skeletal muscles through the same overflow phenomenon seen in the liver.
When pancreatic beta cells can no longer keep pace with rising insulin resistance, blood glucose rises rapidly, leading to type 2 diabetes diagnosis within just 1-2 years. The culprit is fatty infiltration of the pancreas - the same mechanism behind insulin resistance in other organs. Modern imaging confirms that fatty pancreas is clearly associated with type 2 diabetes - diabetic patients have more pancreatic and hepatic fat than non-diabetics, and the more pancreatic fat, the less insulin secreted. The removal of just 0.6 grams of pancreatic fat can reverse type 2 diabetes.
Two vicious cycles sustain type 2 diabetes: the hepatic and the pancreatic. The hepatic cycle develops first, where excessive glucose and fructose consumption leads to hyperinsulinemia, fatty liver, and insulin resistance. The pancreatic cycle begins when the fatty liver exports fat as VLDL to other organs, including skeletal muscles and pancreas. As the pancreas becomes clogged with fat, it cannot secrete insulin normally. The fundamental cause is excessive dietary consumption of sugar - primarily glucose and fructose. Simply put, type 2 diabetes is entirely caused by too much sugar.
8장
The Fructose Factor: Sugar's Toxic Legacy
In 2009, Dr. Robert Lustig's lecture "Sugar: The Bitter Truth" went viral with its message that sugar is toxic, echoing Dr. John Yudkin's warnings from 1957. While dietary guidelines warned about sugar in 1977, this message was overshadowed by anti-fat hysteria. Sugar consumption rose steadily until 2000, followed by increasing diabetes rates - even in countries with low obesity rates, suggesting sugar's unique role in diabetes development.
Following Paracelsus's principle that "the dose makes the poison," fructose consumption has risen dramatically from 15-20 grams daily before 1900 to 55 grams by 1994. The development of high-fructose corn syrup (HFCS) in the 1960s accelerated this trend, as food companies replaced sucrose with this cheaper alternative in countless processed foods. By 2000, fructose consumption had increased fivefold in just a century, with adolescents consuming up to 25% of their calories as added sugars.
Fructose is particularly harmful compared to glucose because of how the body metabolizes it. While glucose is distributed throughout the body with only 20% processed by the liver, fructose targets the liver exclusively. For a 170-pound person consuming equal parts glucose and fructose (as in sucrose), the entire body metabolizes the glucose, but the 5-pound liver must process all the fructose. The liver converts fructose to glucose, lactose, and glycogen without limitations, and when glycogen stores fill, excess fructose becomes liver fat through de novo lipogenesis (DNL). Fructose can increase DNL fivefold and boost liver fat by 38% in just eight days - making it approximately 34 times more likely to cause fatty liver than glucose.
Since 1980, research has shown that fructose overfeeding rapidly induces insulin resistance. Healthy subjects consuming 1000 extra calories of fructose daily showed 25% worse insulin sensitivity after just one week, while glucose overfeeding produced no similar effect. This rapid progression suggests that decades of high fructose consumption would inevitably lead to widespread diabetes.
Data from over 175 nations links sugar intake directly to diabetes, independent of obesity. Asian sugar consumption is rising nearly 5% annually, resulting in a diabetes epidemic. In 2013, approximately 11.6% of Chinese adults had type 2 diabetes despite having an average BMI of only 23.7 (considered ideal). This presents an apparent paradox: despite traditionally consuming white rice (refined carbohydrates), Chinese populations historically had low diabetes rates because they consumed almost no sugar.
Fructose is particularly toxic because only the liver can metabolize it, converting virtually all ingested fructose into new fat, directly causing insulin resistance. The liver processes fructose without limits - more fructose leads to more fat production independent of insulin, with no natural satiety pathways to curb intake. Sugar (sucrose) plays a dual role in disease: its glucose component stimulates insulin production, while its fructose component directly produces fatty liver and insulin resistance. This makes sugar far more dangerous than starches containing only glucose.
9장
Breaking the Cycle: The Path to Reversal
The conventional treatment for type 2 diabetes has been insulin injection, a triumph for type 1 diabetes but a disaster for type 2. While type 1 diabetics need insulin replacement due to deficiency, type 2 diabetics already have excess insulin. High-dose insulin therapy in type 2 diabetics creates "double diabetes" - they develop all the hyperinsulinemia problems while merely hiding glucose in tissues rather than addressing the fundamental problem of excess sugar and insulin.
Multiple studies show insulin treatment dramatically increases mortality risk - by up to 279% in some studies. Insulin facilitates every step of atherosclerosis, from inflammation to plaque formation. Similarly, as a growth hormone, insulin drives tumor development - women with highest insulin levels have 2.4 times higher breast cancer risk, and insulin therapy increases colon cancer risk by approximately 20% per year.
Standard diabetes medications represent a fundamental trade-off between glucotoxicity and insulin toxicity. Insulin, thiazolidinediones (TZDs), and sulfonylureas reduce blood glucose but increase insulin, causing weight gain with no net clinical benefit. Metformin and DPP-4 inhibitors are weight neutral but offer minimal benefits. Only acarbose, SGLT2 inhibitors, and GLP-1 analogs lower both glucose and insulin, causing weight loss and reducing complications.
Bariatric surgery proves that type 2 diabetes is reversible when we treat the cause (hyperinsulinemia) rather than just the symptom (hyperglycemia). In virtually all cases, type 2 diabetes completely disappears after bariatric surgery, even in 500-pound patients with twenty years of disease. This rapid reversal occurs within weeks, long before substantial weight loss. The mechanism is simple: sudden, severe caloric restriction depletes liver glycogen in 24 hours, forcing the body to burn fat - particularly the ectopic fat around organs that causes metabolic syndrome.
However, we can achieve the same benefits without surgery if we understand why it works. The simplest explanation is correct: all bariatric surgeries create sudden, severe caloric reduction, forcing the body to burn ectopic fat from organs. This removes the root cause of diabetes - the overflowing fat in liver and pancreas cells.
The solution becomes obvious: stop putting sugar in (low-carbohydrate diets) and burn remaining sugar off (intermittent fasting). This natural, drug-free approach short-circuits the vicious cycle of excess glucose leading to insulin resistance and disease. Dr. David Unwin transformed his practice by teaching patients that starchy foods like bread raise blood glucose more than table sugar. His 160 patients achieved average weight loss of 9kg and significant HbA1c improvements, while his practice saved 50,000 annually on diabetes medications.
Understanding diabetes development allows implementing three essential food rules for reversal: 1) Avoid fructose and all sweeteners, 2) Reduce refined carbohydrates and enjoy natural fats, and 3) Eat real food in its natural state. Sometimes these rules aren't enough for severe cases, requiring the oldest dietary intervention known to humans - fasting.
Unlike continuous caloric restriction which triggers metabolic slowdown, fasting actually increases metabolism. Studies show that while chronic caloric reduction drops basal metabolic rate by up to 30%, fasting for four days increases it by 12%. This occurs because during fasting, the body accesses stored body fat for fuel rather than entering "starvation mode." This metabolic advantage makes fasting far more effective for long-term weight loss than daily caloric restriction.
Both intermittent fasting and low-carbohydrate, healthy-fat diets effectively reduce insulin and can reverse type 2 diabetes. Fasting provides the maximum insulin reduction, while very low-carb diets deliver about 71% of fasting's benefits without actual fasting. The two approaches are complementary rather than competing - they can be combined for maximum effectiveness.
With proper understanding of diabetes and effective treatments, complete eradication of type 2 diabetes is possible - naturally, without cost, without surgery. This vision means no more diabetic complications: no kidney disease, eye disease, nerve damage, foot ulcers, or infections. It means fewer heart attacks, strokes, and cancers, and no need for diabetic medications.
Type 2 diabetes, obesity, fatty liver, and metabolic syndrome have become the modern equivalent of the Bubonic plague, spreading across all genetic boundaries worldwide. We must stop pretending type 2 diabetes is chronic and progressive - it's clearly a dietary disease requiring dietary treatment. The treatments that cure diabetes all share one characteristic: they lower insulin. The doorway to a diabetes-free world has opened through the oldest interventions known: low-carbohydrate, healthy-fat diet and intermittent fasting.
10장
A Revolution of Hope: Changing the Diabetes Paradigm
Despite this book's deep exploration of diabetes, it's ultimately about hope - hope for eradicating type 2 diabetes within a generation, erasing metabolic syndrome diseases, and recovering both financial costs and human suffering using knowledge alone as our weapon.
Dr. Fung recounts his medical journey from conventional training through his awakening about diabetes treatment. As a kidney specialist, he saw countless diabetic patients deteriorate despite medication adherence. After decades of treating thousands of patients, he realized diabetes medications made no real clinical difference. This suspicion was confirmed by landmark studies in 2008 that proved glucose-lowering medications were useless against complications.
His breakthrough came from questioning causality - asking "why" people get fat and develop diabetes. Recognizing the astronomical failure rate of caloric reduction diets, he identified hormonal imbalance, primarily insulin, as the key to obesity. This insight revealed a paradox: if excess insulin causes obesity, why prescribe insulin to overweight diabetics? Further investigation led to understanding that obesity and type 2 diabetes are manifestations of the same underlying problem - too much insulin. The solution became clear: lower insulin through dietary changes, not pharmaceuticals.
In 2011, Dr. Fung established the Intensive Dietary Management program with Megan Ramos to counsel patients on low-carbohydrate, high-fat diets. Initially, results were disappointing as patients misunderstood what constituted low-carbohydrate foods. Having followed low-fat diets most of their lives, this new approach was foreign to them, prompting Dr. Fung to seek a simpler solution. Inspired by a friend's mention of "cleanses," he investigated fasting in medical literature and began guiding patients through diet and fasting regimens with remarkable results. Patients on insulin for decades eliminated medications within weeks, lost significant weight, and reported increased energy rather than the weakness they expected.
Type 2 diabetes, currently the leading cause of blindness, kidney failure, amputations, heart attacks, strokes, and cancer, doesn't have to define our future. The knowledge contained in The Diabetes Code offers the path to reversing type 2 diabetes, marking not an end but a beginning - a new dawn of hope.
