How a thin person with diabetes reversed her type 2 diabetes

Alarm clock and utensils

Fasting to reverse type 2 diabetes

I received a letter from reader Sarah, who has successfully used low-carbohydrate high-fat diets and intermittent fasting to reverse her type 2 diabetes. Interestingly, she is not particularly overweight as measured by body mass index, yet still suffered from T2D. At her heaviest, she only had a BMI of 24.9, which puts her in the ‘normal’ range. She writes:

The letter

I immigrated to US from P.R. China in the end of 1998 when I was 31 years old; I weighed about 55 kg (121 lbs). While I was in China, I lived thousands of miles away from my family, so I had sort of an intermittent fasting life style from age 19 to 31 years old. The meals in China were mostly vegetables and very little protein. I had an annual physical check up every year, but was never told of any abnormal blood results.

After I immigrated to the U.S., my lifestyle suddenly changed from one meal per day to three meals consisting of mainly grains with little fat and protein. I gained about 25 pounds (11 kg) in a couple of years, my weight did not continue going up. My heaviest was about 145 pounds (66 kg). When I was diagnosed with diabetes in Dec 2004:

  • Weight: 142 pounds (64 kg)
  • Height: 5 feet 4 inches (163 cm)
  • HbA1c: 9.4
  • FG: 214

I was told to exercise, so I started yoga shortly after my diagnose. I lost about 10 pounds (5 kg) and 2 inches (5 cm) from my waist but still required metformin. In the spring of 2005, I relocated to Galveston from Houston because of my work as an engineer. My endocrinologist sent me to a nutritionist who measured my after meal glucose in her office, it was near 200 mg/dl (11.1 mmol/l) three hours after lunch which was only one low-fat pita bread. I was devastated, my previous family doctor always told me that if I exercise daily, my blood sugar will come down to normal, so I believed him. I was doing my yoga every day, but I thought that would be enough.


I volunteered to Joslin Diabetes Center’s clinical research in July 2006, and traveled to Boston as a research subject. I noticed I had gained about 5 pounds (2 kg) after adding 5 mg of glyburide so I stopped. In Boston, I was told that I need to gain muscle and reduce body fat because my weight was 144 lbs (65 kg) and my total body fat was 32.3% from DXA result.

After returning to Galveston from Boston, I started to add running and weights, and my weight went down to 132 lbs (60 kg) in a couple of months, and noticed my blood sugar would drop about 100 points (from 240 to 140 mg/dl – 13.3 to 7.8 mmol/l) in 10 minutes on treadmill. So I keep running about 45 minutes five times a week and doing weights about 20 minutes three time a week, and a couple of hours of yoga every week.

My weight would fluctuate from 132 lbs (60 kg) in winter and climb to 145 lbs (66 kg) in summer. My waist fluctuated from 30 to 31 inches (76 to 79 cm). I watched my carb intake according to the American Diabetes Association food plan, and noticed I could never consume the carb recommendations without elevating my blood sugar through the roof. As a matter of fact, my blood sugar will spike to about 100 points with ¼ of a slice of bread for lunch. I tested over and over, I could not explain. However, I corrected my after meal spikes with running on treadmill for 10 to 15 minutes every lunch.

In about 2nd quarter of 2009, I started a vegan diet which consisted mainly of grains, beans, vegetables only not even eggs or cheese, after watch PBS on one Saturday. Vegan diets supposed to reverse type 2 diabetes, as claimed by vegan promoters. During this period, I noticed my triglycerides had climbed up from 85 to 228, and my thyroid TSH also went up. After I got my lab test from Jan 21 2011, I decided to end my low-fat vegan experiment. I started my experiment with one problem, then I ended with more problems. I attended the vegan doctor’s presentation in Houston, and asked him about my triglycerides, he could not explain to me. The vegan diet did not help me with my diabetes, but I learned valuable information about how to use food as medicine. I also learned with increase in carbs, my triglycerides will go up which is a bad sign for my heart.


In February 2011, I started to experiment with the low-fat vegetable diet, after about a year, all my co-workers and my friends noticed my skin and palm turned into a green yellowish and my hands and feet were cold all the time with swelling. My face swelling every morning and my hands and feet swelling in the afternoon. I realized there is something wrong with my experimental food plan. I was told it is a degenerative disease so I accepted my fate. Continued with low-fat vegetables almost no saturated fat diet. Internally, I experienced fatigue every day which I could not explain.

By Oct 2014, my HbA1c climbed to 7.9, I almost broke down in my endocrinologist’s office. He comforted me and said it is not a big deal, he sees patients with HbA1c above 10 every day. I am one of his good patients.

I knew the grains triggered my blood sugar spike, so I started eliminate all grains and beans from my diet completely, but I was still afraid of fat especially saturated fat. I bought Dr. Richard Berstein’s books, he stated rib-eye steak is better than the lean steak for diabetes. I was shocked. Fat would give me diarrhea since I was a little girl, so I have been avoiding eating any saturated fat all my life. I grew up in food rationing era in China where almost no saturated fat was available from markets beside government stores.

So I started to understand the reasons for why vegan never worked for me. It was not dietary fat that caused me to be diabetic. I had eaten almost no fat in my whole life. I added saturated fat such as beef, butter and coconut oil to my diet, I found the Diet Doctor website. Dr. Andreas’s experiments in a diabetes conference meal was very similar to my own experiments. With the ketogenic diet, I was able to reduce my HbA1c from 7.9 (Oct 2014) to 5.9 (June 2015) in about eight months. I kept my carb intake to about 20 grams which mainly came from vegetables.

SarahXieApr2017By August 2015, I discovered Dr. Fung through I have been practicing intermittent fasting ever since. By March 2016, my HbA1c was 5.6. I lost about 12 lbs (5 kg) since I started the ketogenic diet (Nov 2014) my waist is 28.5 inch (72 cm), and weight 127 to 130 lbs (58 to 59 kg) through out a month period. I no longer have swelling on my face, hands, and ankles.

Since I started the ketogenic diet, my blood sugar would surge during exercise by about 80 points. For example, I would start at 110 mg/dl (6.1 mmol/L) before tennis, after 45 minutes my BG would 195 mg/dl (10.8 mmol/L) I tested over and over. I tried to use chocolate or cheese before exercising, none of which was able to lower or keep my blood sugar from surge. Out of desperation, I took a teaspoon of coconut oil then went on exercising, I found my blood sugar is remarkably stable during and after exercising. Before I found the secret of coconut oil, I could not begin to walk my dogs with blood sugar at 90 mg/dl (5 mmol/L), because it would surge to near 200 mg/dl (11.1 mmol/L), now I can take a teaspoon of coconut oil, then go to do exercising without experience any blood sugar surge. I am no longer depressed about being a diabetic.


That’s amazing work, Sarah. With these detailed records, you can see how LCHF and IF help even with a so-called ‘thin’ diabetic. Asians tend to get type 2 diabetes at a lower BMI than North Americans, with the average Chinese type 2 diabetic having only a BMI of 23.7 at diagnosis, not unlike Sarah. Even with a waist of 31 inches (79 cm), you can have type 2 diabetes. The important factor here is the intraorganic deposition of fat (inside the liver and pancreas) rather than the total fat mass.

Nevertheless, the pathophysiology of ‘regular’ and ‘thin’ diabetes is similar, and responds equally well to dietary interventions. It’s striking that even 10 years of diabetes on medications can be reversed completely since an HbA1c of 5.6 without medications defines Sarah as non diabetic. Congratulations!

Jason Fung


How to Reverse Type 2 Diabetes

Intermittent Fasting for Beginners

A Ketogenic Diet for Beginners

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