As a holistic nutritionist, it is important for me to provide my readers and clients with information to improve their health and to share with others. Much of this information is not readily available, may be considered controversial, or is dismissed by the main stream as anecdotal or not supported by science. Yet the truth is that many people have benefited and there is real science to back it up.

I recently came across the work of Dr. Jason Fung, a Toronto based specialist in kidney diseases who treats patients with end-stage kidney disease requiring dialysis. Most of them are obese and diabetic. While some may consider his work controversial, I have seen the results of his advice first hand in addition to the success stories he provides.

According to Dr. Fung Type 2 diabetes is fully reversible and preventable and he does this without using medications or surgery. The key is to control the insulin resulting from the diet and to do that using intermittent fasting.

I encourage you to read at least one of his three books or for those of you who prefer learning through listening and watching, view his many presentations on YouTube. The books are a progression of his knowledge sharing. The Obesity Code: Unlocking the Secrets of Weight Loss was published in 2016. It discusses the current obesity epidemic – how it has developed and how you avoid becoming obese. There is a strong link between being obese and developing Type 2 diabetes. In 2018 he wrote The Diabetes Code: Prevent and Reverse Type 2 Diabetes Naturally. This book focuses on the diabetes epidemic, the actual causes of diabetes, how not to treat Type 2 diabetes, and his proven methods for successfully treating Type 2 diabetes. The third book is The Complete Guide to Fasting: Heal Your Body Though Intermittent, Alternate-Day, and Extended Fasting. This book provides more detail on various fasting techniques used to lose weight and manage and reverse Type 2 diabetes.

Following is a summary of the key points made in the books. Again, I encourage you to read the books to get the complete story and they include all the sources for his findings.

There is much deception around calories. The truth is that eating fewer calories will cause your body to burn fewer calories. This is part of our adaptive nature to the days of our ancestors when food was not available at every corner. Our basal metabolic rate slows down to compensate for less fuel. If it did not our ancestors would have not had the energy to hunt and survive while they had limited food. While there will be some short-term weight loss with restricted calories, eventually a plateau is reached, and weight loss stops.  And, as virtually everyone experiences when resuming how you ate before the “diet” the weight comes back on quickly and often exceeds where you started.

Obesity is not caused by an excess of calories or by a lack of exercise, but by a hormonal imbalance in the body. Hormones regulate appetite, fat storage, and blood sugar levels. Leptin regulates body fat and is involved in setting the body weight. Ghrelin regulates hunger. Peptide YY and cholecystokinin regulate feeling full and satisfied. But, only two hormones cause weight gain – cortisol and insulin. Therefore, to lose weight we must reduce these hormones. We can reduce cortisol through stress reduction techniques and we can reduce insulin through dietary techniques of what to eat and when to eat.

Dr. Fung recommends a moderate fat, moderate protein, low carbohydrate diet. For most people this means reducing consumption of added sugars, reducing consumption of refined grains, moderate intake of protein, increase consumption of natural fats, and increase consumption of fiber and vinegar. One key new learning for me was the moderation of protein intake. Too much protein can cause blood sugar levels to rise leading to a subsequent increase in insulin.

To reduce insulin enough to lose weight and to reverse Type 2 diabetes Dr. Fung recommends a variety of intermittent fasting programs. It is important to clarify the terms “intermittent” and “fasting.” Intermittent means there are periods of time when you do not eat any food. During fasting periods, you can have water, tea, coffee, bone broth, and add fats such as coconut oil and butter to the coffee or tea. This is critical to understand because a complete fast with no water or food will lead to dehydration which will impact metabolism. Another key point is that the basal metabolic rate does not slow down with intermittent fasting.

Dr. Fung describes a variety of fasting plans. The basic plan is 16 hours of fasting and an 8-hour window of eating. This can be accomplished by skipping breakfast (but again you are allowed coffee, tea, or bone broth with specified limitations) and eating lunch and finishing dinner between noon and 8 PM. This is a good plan for someone just looking to lose some weight.

The 24-hour plan consists of skipping breakfast and lunch 3-4 days per week and having three meals the remaining days of the week. There are also 36-hour plans, 42-hour plans, and 7-14-day plans. Again, the best plan for an individual depends on their specific objectives and their present condition.

Again, I encourage you to read the book or view the YouTube presentations as in this limited space I can only share the highlights.

Bernard Rosen, PhD is a Nutrition Consultant and Educator. He works with individuals, groups, and at corporations to create individualized nutrition and wellness programs. His office is in Mequon, WI. To learn more or to schedule an appointment, e-mail at, call (262) 389-9907 or go to