Evidence-Based Nutrient Recommendations

Pre-Type 2 Diabetes and Lean Vegans


by Susan Papuga



Recently, I’ve been contacted by a small group of lean, pre-diabetic vegans. I had previously not heard of lean vegans developing pre-diabetes, but it turns out that it’s not uncommon. In this article, Susan Papuga has been kind enough to share well-researched findings on the subject.

–Jack Norris, RD

Please see Diabetes: Tests and Diagnosis from Mayo Clinic for a reference range for the numbers discussed below.

Pre-Type 2 Diabetes and Lean Vegans

The majority of people with type 2 diabetes are overweight and suffer from hyperglycemia (high blood sugar) due to insulin resistance. However, there is also a condition in which thin people suffer from hyperglycemia. Few studies have been done on lean diabetics and are primarily on Asian populations. Many of these studies have found that lean type-2 diabetics are suffering from a deficiency of the insulin-producing beta cells rather than from insulin resistance. An even smaller subset rarely mentioned are lean vegans with high blood glucose; further research is needed to determine the cause of their pre-diabetes or diabetes.

The International Diabetes Foundation has developed a document, Guideline for Management of Postmeal Glucose (PDF), which states, “Although control of fasting hyperglycaemia is necessary, it is usually insufficient to obtain optimal glycaemic control. A growing body of evidence suggests that reducing postmeal plasma glucose excursions is as important, or perhaps more important for achieving HbA1c goals.” Their recommendation is that two-hour postmeal (also known as postprandial) plasma glucose should not exceed 140 mg/dl (7.8 mmol/l) as long as hypoglycemia is avoided.

In order to meet that goal for a lean vegan who is pre-diabetic or diabetic, careful consideration needs to be paid to diet. One challenge is how to prevent postprandial spikes while reducing carbohydrate and still maintaining adequate body weight. The Eco-Atkins diet can be an effective path to follow with higher fat and protein consumption from nuts, seeds, avocados, soy foods, and seitan—all helping to provide needed calories. Carbohydrate should be chosen wisely, emphasizing high fiber and low glycemic foods.

The Guideline further states, “Self-monitoring of blood glucose should be considered because it is currently the most practical method for monitoring postmeal glycaemia.” For a lean vegan, this is an important step in taming impaired glucose metabolism. For a few in our group of lean vegans, our fasting glucose was only slightly elevated while an HbA1c test and/or postprandial glucose identified pre-diabetes.

My first indication of impaired glucose metabolism was during a routine lab which showed a slightly elevated fasting glucose of 101. I started testing my fasting and postmeal glucose at home and mentioned to my doctor that I was seeing some high numbers for postmeal, up to 185. A person with normal glucose metabolism rarely goes over 140 postprandial. An oral glucose tolerance test confirmed a pre-diabetes diagnosis, and then began my journey to find a way to lower those numbers while eating a healthy vegan diet.

Personally, I’ve had success at keeping my fasting glucose under 100 mg/dl and postprandial glucose under 140 mg/dl with a diet similar to Eco-Atkins. I found that the processed grains in breads and pasta and many mid- to high-glycemic index foods, even in modest amounts, will cause a high postprandial spike. To keep glucose low and slow, the high fiber carbohydrate are best. I’ve stopped eating dried fruit and eat low glycemic index fresh fruit only in small servings; instead, I fill up with hull-less barley (1), soybeans, legumes, chia seeds, wheat bran, non-starchy vegetables, nuts, seeds, avocado, and seitan.

Tracking daily nutrients on Cronometer.com has been invaluable for meeting the RDA targets. Consequently, my lab results are coming back with great numbers: low cholesterol (high HDL), low inflammation, low blood pressure, normal glucose, and HbA1c at 5.0. This diet works well for me and the other vegans in our group. We’ll continue to monitor our glucose and labs, adjusting when needed, but overall we are quite pleased, as are our doctors, with the outcomes.


Last updated August 2015

1. Barley can be hulled or hull less. Hull-less barley has a lower glycemic index and higher nutrient profile.

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