Diabetes expert Dr. Keith Runyan blogs as the Diabetic Ketogenic Athlete, where he details his own glucose management successes and challenges in extraordinary detail. The good doctor was diagnosed with Type 1 diabetes as an adult, in 1998, and has followed a low-carbohydrate diet since 2012.
Since retiring from his medical practice, he’s written two books on attacking diabetes with a ketogenic diet, and he’s also offered online diabetes and weight management coaching. Oh, he’s also an Ironman and a weightlifter, all of which, combined with his medical background and data-driven perspective, makes him one of the world’s most careful and learned commenters on the experience of Type 1 diabetes, the effect of the low-carbohydrate diet, and the benefits of exercise.
If you want to learn about why Dr. Runyan initially chose a low-carb way of eating, you can read it right here: he wrote us an essay on the topic in 2016. I can also recommend his lectures, which were influential to me when I decided to embark on my own low-carb journey.
We reached out to him to get his up-to-the-minute takes on glucose management, the benefits of low-carb living, and the benefits of exercise and weight control for people with T1:
Can you explain what your personal blood sugar targets are, and how you arrived at them?
My mean and target blood sugar goal is 100 mg/dl. This is largely based on the average blood sugar of 564 metabolically healthy nondiabetic subjects who wore continuous glucose monitors (CGM) for several days in five different studies. The largest of these five studies had 434 subjects. The mean CGM readings were 98?104 mg/dl.
I also have a goal of achieving a standard deviation of blood sugar less than 25 mg/dl. This small study is just one of many suggesting that varying blood sugars, typically after meals,
results in increased generation of oxidative stress, reactive oxygen species, and inflammation:
known mechanisms of diabetic complications. In the studies I referenced above, the standard deviation of normal glycemic variability was found to be 25.2 mg/dl or less.
Your targets are different than those set by the dean of the low-carbohydrate regimen, Dr. Bernstein, who recommends a goal of 83 mg/dL. How does your thinking differ from his?
I used Dr. Bernstein’s target in 2014 and achieved an average blood sugar of 85 mg/dl. I had frequent low blood sugars, even though the vast majority were asymptomatic.
Upon further research of the medical literature, I was unable to find a benefit to maintaining a lower blood sugar than 100 mg/dl. It is also apparent that asymptomatic hypoglycemia has the potential toincrease the risk of a fatal low blood sugar. Unfortunately, 4?10% of persons with T1DM diefrom hypoglycemia. Low blood sugars are something to be taken very seriously. So for me, a target blood sugar of less than 100 mg/dl was risking death without any potential for benefit.
My general advice is that the target blood sugar should be as close to normal as can be safely achieved without low blood sugars.
In your coaching practice, what type of goals do you set for your clients? What factors lead you to recommend tighter vs looser control, or higher vs lower blood glucose targets?
Most of my coaching clients are very motivated to improve their blood sugar control. Deciding on a specific target blood sugar is different for every individual and depends on their current level of blood sugar control, presence of diabetic complications, and frequency of low blood sugars. Avoidance of low blood sugars is the highest priority to ensure safety in treating T1DM.
People attribute many wonderful benefits to the ketogenic diet: increased energy, increased mental clarity, reduced hunger, etc. How many of these did you perceive when you made the switch, and have they lasted over the years?
Personally, my transition to a ketogenic low-carbohydrate diet on February 8, 2012 was seamless, without any adverse effects. Prior to starting, I did not have any problems with weight, hunger, reduced energy, or mental clarity, nor did I notice any changes in these areas after starting my ketogenic diet. Now, more than seven years later, I continue to thrive on a ketogenic diet without diabetic complications, and with a Coronary Artery Calcium score of zero, which is indicative of an absence of atherosclerotic heart disease.
In the past you’ve theorized that a ketogenic diet may protect against the symptoms of hypoglycemia, and even potentially against some of its adverse effects. What’s your current thinking on this?
Nutritional ketosis, which results from a ketogenic diet, may protect against the symptoms of hypoglycemia – with an emphasis on “may” – because ketones are a preferred fuel for the brain. With that said, in nutritional ketosis the level of ketones is generally low (< 3 mmol/l) and likely is not making a large contribution to the brain’s fuel supply.
However, the other known cause of lack of symptoms of hypoglycemia is “hypoglycemia unawareness.” This is an adaptation of the brain to low blood sugar, that causes subsequent low blood sugars to result in fewer or no symptoms. Even just a single hypoglycemic episode can trigger it. This is potentially dangerous because the symptoms of hypoglycemia are the body’s warning sign to correct a low blood sugar. Hypoglycemia unawareness thus delays the correction of hypoglycemia due to the lack of symptoms. This delay in correcting hypoglycemia can result in death, especially if it occurs while sleeping, which is when hypoglycemia unawareness is further accentuated.
Since it is almost impossible to know how much of asymptomatic hypoglycemia is due to ketones versus hypoglycemia unawareness, one should err on the side of safety and simply avoid hypoglycemia to the greatest possible extent. The bottom line here is that while ketones in the setting of nutritional ketosis may provide an alternative brain fuel during hypoglycemia, this is not a reason to tolerate hypoglycemia. Hypoglycemia has no benefit; only harm can result from it.
You’ve also suggested that diabetic complications in T1’s are likely due to insulin resistance, in addition to chronic hyperglycemia. Can you expand on that?
There is good evidence from many different sources that in both T1DM and T2DM insulin resistance and hyperinsulinemia result in endothelial cell (the cells that line the inside of artery walls) inflammation and subsequent atherosclerosis (hardening of the arteries). This is the leading cause of death of those with both T1DM and T2DM.
It is also well established that high blood sugars result in glycation which damages tiny blood vessels leading to diabetic complications such as diabetic retinopathy (eye disease), nephropathy (kidney disease), and neuropathy (nerve damage).
The low-carbohydrate diet addresses both of these problems in those with diabetes by reducing both blood sugars and insulin doses in those with T1DM, and often facilitates discontinuation of insulin altogether in those with T2DM.
Your diabetes coaching service also focuses on weight management. How important is weight management for people with T1D?
Although persons with T1DM have traditionally been thought to be lean, obesity in this population has increased at a faster rate compared to the general population. Currently, about 50% of patients with T1DM are either overweight or obese. Persons with T1DM develop overweight and obesity before 30 years of age more frequently than the general population and have higher body fat mass than non-diabetics.
Those with T1DM with signs of insulin resistance (including metabolic syndrome and obesity, as occur in those with T2DM) are considered to have “double diabetes.” This condition increases the risk of atherosclerotic heart disease. Thus, reversing overweight, obesity, and insulin resistance in those with T1DM will reduce the risk of future heart disease and early death. Losing excess body fat is challenging for most and is further complicated by having to take insulin injections. I help my clients overcome this challenging problem by assisting them with formulating a low-carbohydrate diet, exercise program, and careful insulin dose decrements while improving glycemic control.
You’re an extremely committed athlete, and practice both cardio and weight-lifting. Do these exercises have benefits that are of special interest to a person with Type 1 diabetes?
I think the major benefit of exercise for those with T1DM is in preventing or reversing insulin resistance which in turn reduces the risk of heart disease. Exercise, by improving insulin sensitivity, allows for a further reduction in insulin doses above and beyond the major effect of a low-carbohydrate diet. Of course, exercise is beneficial in numerous respects for everyone.
Exercise can make blood sugar management more challenging. Do you find yourself accepting a less stringent level of glycemic control in order to exercise?
Exercise can make controlling blood sugars more difficult, but accepting a less stringent level of glycemic control in order to exercise is neither necessary nor desired. I started exercising regularly in 2007 and have sorted out what works and what doesn’t when it comes to controlling blood sugar while exercising daily.
I am aware that some with T1DM start exercise with a high blood sugar anticipating that their blood sugar will drop during exercise. Conversely, some experience high blood sugar after exercise. I have personally experienced both. However, I eventually discovered that both basal and bolus insulin as well as the type, intensity, duration, and timing of exercise can be adjusted to prevent low and high blood sugars associated with exercise.
Can you describe your coaching practice?
I meet with clients on Skype and discuss the issues that concern them. I provide customized suggestions to help my clients achieve their goals. The most common issues are improving blood sugar control, weight loss, and solving blood sugar excursions related to exercise.