Book Review: The Diabetes Code
Author Jason Fung, MD, of the University of Toronto has taken “Ockham’s razor” to simplify the management of type 2 diabetes. William of Ockham (1287-1347) was an English friar and philosopher famous for postulating that with complex problems, the hypothesis with the fewest assumptions is usually correct.
In his book The Obesity Code (2016), Dr. Fung reformulated our understanding of obesity by arguing persuasively that obesity is a hormonal illness of excess insulin. Whenever we eat, especially carbohydrates, we secrete the hormone insulin to drive blood sugar into cells. Insulin is more importantly a fat storage hormone that blocks the burning of fat and causes excess sugar to be turned into fat through lipogenesis (the making of fat in the body). Repeatedly eating carbohydrates causes chronically high insulin levels and the steady accumulation of fat.
Besides the benefits of a low carbohydrate diet, Dr. Fung stresses the importance of fasting to lower the insulin level enough to begin burning off body fat. Dr. Fung points out that we have been focused only on what we eat and not enough on how often we eat. Humans have spent most of their time on earth eating just one meal a day. Eating three meals a day is cultural and contributes to the epidemic of overweight and obesity, especially with our increased intake of refined carbohydrates.
In The Diabetes Code, Dr. Fung furthers this same argument to show that type 2 diabetes is caused by insulin resistance. Doctors have known this for a long time, but Fung elucidates how insulin resistance occurs. The repeated secretion of insulin that causes obesity next leads to fatty liver and our body’s protective mechanism over time is to become resistant to insulin. This results in the high blood sugar of type 2 diabetes (type 1 diabetes, a completely different illness, comes from the body losing all its ability to secrete insulin).
Dr. Fung discusses that while many of the drugs used to treat type 2 diabetes lower blood sugar, they make the underlying disease worse by increasing body fat and insulin resistance. The biggest culprit here is the use of insulin injections. In the U.S. we spend over 23 billion dollars on drugs for type 2 diabetes, more than the total revenues of professional football, baseball and basketball combined. In Dr. Fung’s clinic, most patients with type 2 diabetes have complete reversal off medications by three months.
The approach to preventing and reversing diabetes described in The Diabetes Code is simple. The nutrition is healthy fats, low carbohydrates and intermittent fasting. Dr. Fung will often use fasting periods of three days or longer to get insulin levels low allowing the body to recover from insulin resistance. Healthy nutrition continues for life with healthy fats: nuts, seeds, fatty vegetables such as avocado, quality fish and meat. All refined carbohydrates and sugars are avoided. 12-16 hour fasting periods are built into the daily routine (stay hydrated; coffee and tea are allowed). Adults should eat only 1-2 meals a day. Any snacks should be healthy fat and low carbohydrates such as raw nuts.
With The Diabetes Code, Jason Fung, MD, has provided a simple lifestyle approach to preventing and avoiding what has become the most expensive of all chronic diseases. The food and drug industries will not be excited by his method, but it is time for the public to become healthier and to lower the costs of medical care.
Dr. Scherger is an Eisenhower Health Primary Care 365 physician and core faculty member of the Family Medicine Residency Program.