Most medical professionals don’t recommend a ketogenic diet for type 2 diabetes. The standard dietary advice is fairly bullish on carbs.
Meanwhile, cases of this metabolic disorder continue to spiral upwards, especially in the United States. It’s a leading cause of death, and an indirect cause of many other chronic conditions.
How did we get ourselves into this mess? Researchers are still arguing the particulars, but it’s obvious that diet and lifestyle are largely to blame. Too much sugar, refined foods, and calories overall, plus too little exercise, quality sleep, and other important lifestyle practices.
Diet helped get us into this mess, and it may yet help us get out of it. Low-carb diets, research suggests, act as therapy for type 2 diabetes.
This isn’t to say that a keto diet is the only effective anti-diabetes diet. There’s also evidence for a whole foods Paleo diet, for instance. And heck, if we are being really honest about this, a vegan diet has been shown to prevent and reverse type 2 diabetes in some folks, too.
The key similarities across these strategies is that they help people reduce calorie intake, reverse insulin resistance, and improve metabolic health. Keto is not a good fit for everyone, so it’s important not to be dogmatic about it. But it’s also important not to ignore a potentially important tool.
All that said, for diabetics on supervised keto diets, the results are promising. Lower blood sugar, significant weight loss, and less reliance on supplemental insulin—all these findings are highlighted in peer-reviewed literature.
It makes sense. If one’s metabolism can’t process carbs efficiently (as type 2 diabetics’ metabolisms can’t), it’s logical to limit them, at least temporarily.
Obviously that’s a drastically oversimplified scoop on type 2 diabetes. Let’s sharpen our fundamental understanding of the problem at hand, and then see how keto may be able to help.
What Is Type 2 Diabetes?
Type 2 diabetes is a metabolic disorder marked by high blood sugar, high insulin, high blood pressure, high triglycerides, and obesity. Of these biomarkers, clinicians look primarily at blood sugar to make the diagnosis.
You can measure your blood sugar in several ways, but the most common metrics are fasting blood glucose (at least 12 hours of fasting) and a measure of average blood glucose called hemoglobin A1c (HbA1c).
Here’s what the American Diabetes Association regards as normal, prediabetic, and diabetic for fasting blood glucose (FBG) and HbA1c.
- Normal: FBG under 100 mg/dl, HbA1c under 5.7%
- Prediabetes: FBG from 100 to 125 mg/dl, HbA1c from 5.7% to 6.4%
- Diabetes: FBG over 125 mg/dl, HbA1c over 6.4%
Type 2 diabetes is distinct from type 1 diabetes. Unlike type 1 diabetes—which results from autoimmunity in the pancreas—type 2 diabetes is largely a result of lifestyle. This explains why, in America, cases have ballooned by a factor of seven over the past fifty years. Genes haven’t changed, but lifestyles have.
How have lifestyles changed? For one, we’re eating more sweet stuff than ever before. Believe it or not, the average American consumes 17% of their calories from refined sugar. These empty calories are easy to overeat.
The result is weight gain, chronic spikes in blood sugar, and eventually type 2 diabetes. No—“evil insulin” is not the only driver here. But while folks debate the insulin hypothesis, they also gloss over the fact that refined carbs are an easy way to overeat.
We’re also eating more vegetable oils. These industrial seed oils—soybean oil, safflower oil, peanut oil, etc—make foods hyperpalatable and increase inflammation in the body. They’re especially dangerous when cooked. At high heats, the fats in vegetable oils turn to oxidized lipids—nasty compounds linked to accelerated heart disease.
And don’t forget about exercise. We’re moving less and eating more. The less we move, the higher the risk for chronic diseases like type 2 diabetes. Simply walking has been linked to reduced diabetes risk. The trick here is that folks need to actually… well, WALK!
Problems with the hormone insulin are central to type 2 diabetes. Insulin is generally viewed as your primary controller of blood sugar.
The usual story goes like this: When you eat a meal, your blood sugar rises, and your pancreas releases insulin to remove glucose from circulation. In other words, insulin moves blood sugar out of your blood and safely into muscle, liver, and fat cells for storage.
That’s true, but it also misses some important features. Namely, that the first role of insulin is to reduce the release of glucagon (another hormone released by the pancreas). Glucagon drives up blood glucose, whether one is eating carbs or not.
This is why Type 1 diabetics have such a challenging time managing glucose levels! They generally produce NO insulin and must rely on injected insulin to manage blood sugar levels. In the case of the type 2 diabetic, insulin resistance blunts the effects of insulin on suppressing glucagon release, which is a major driver for increased blood sugar levels.
That’s all tough to manage on its own, but if someone consistently overeats—which millions of Americans do—the blood sugar-regulating powers of insulin become overworked. Once blood sugar has saturated its storage capacity (in glycogen), there’s nowhere for insulin to put it anymore. And in this insulin-resistant state, blood sugar stays chronically elevated. From there, it’s a short hop to type 2 diabetes.
How The Keto Diet May Help With Type 2 Diabetes
The ketogenic diet, or keto diet, is a very low-carb diet that promotes a unique metabolic state called ketosis. In ketosis, your liver burns fatty acids (from body fat or dietary fat) to make energy and ketones (which can be broken down and used as energy themselves, as well).
Keto is all about keeping carbs low—usually to around 30 grams per day. It’s not about mainlining fat, as many misinformed influencers suggest. Mainlining fat often means that folks don’t get enough protein. Check out this article on doing keto macros right.
Back to carbs, because keeping carbs low has metabolic benefits for diabetics and prediabetics. Let’s explore those now.
#1: Blood Sugar Reduction
Of the three major macronutrients—carbohydrates, protein, and fat—carbs have the largest blood sugar impact. That’s because carbs break down into simple sugar (or glucose) when digested.
Despite the standard advice, carbs are not good medicine for diabetes. A low-blood sugar event is not a reason to gleefully consume a candy bar. It’s a reason to avoid them and eat more consistently timed meals full of healthy, whole foods.
Physicist RD Dikeman, who has helped his son navigate type 1 diabetes for over 15 years, makes the case that a low carb, high protein diet plays to the “law of small numbers.” Rather than taking in a ton of carbs and trying to “cover” them with insulin (from a syringe in the case of Type 1’s, or our bodies for everyone else), eating this way helps maintain modest, even blood sugars. No more cresting highs that lead to crashing lows.
Yes, candy will increase your blood sugar and even help you feel better momentarily—but in the chronic sense, this is a terrible method to diabetes management. Researchers have shown, for instance, that high-carb diets worsen hyperglycemia (high blood sugar) in non-insulin dependent diabetics.
The keto diet limits carbs by design. As a result, you see fewer spikes in blood sugar and lower average blood sugar in diabetic populations.
#2: Insulin Function
Patients with advanced type 2 diabetes need supplemental insulin to regulate their blood sugar. They need that extra insulin because they can’t regulate blood sugar with their own, internally-produced insulin.
The keto diet may help improve insulin function in type 2 diabetics. In a study published in Nutrition and Metabolism, the majority of type 2 diabetics enrolled were able to drop their insulin medications after 24 weeks of ketogenic dieting.
#3: Weight Loss
Along with blood sugar reduction, weight loss is a primary therapeutic goal for type 2 diabetics. Keto isn’t a magic weight loss diet, but it can help reduce hunger hormones, which often translates into reduced daily caloric intake. Over a period of weeks and months, a mild caloric deficit can nurture sustainable fat loss.
#4: Whole Foods Focus
The Standard American Diet (SAD, if you will) is the main villain in this narrative. It’s hyperpalatable, it’s inflammatory, and it’s bursting with refined sugar. That’s a recipe for type 2 diabetes.
The keto diet recommended by my former coaches is grounded in real foods like meat, fish, nuts, vegetables, and olive oil. These foods foster a healthy metabolism, and are pretty darn good for body composition, too.
To be clear, keto isn’t the only diabetes diet with supporting evidence. A Paleo diet, for example, has also been shown to improve blood sugar regulation and heart disease risk factors in patients with diabetes.
This suggests one needn’t eliminate carbs entirely to improve diabetes, though that is one option. And while it should go without saying—NO option is perfect for everyone. To learn more about the ketogenic diet and who should be careful with it, check out this article.
Keto for T2D: Clinical Evidence
Eating a low-carb diet for type 2 diabetes sounds good in theory. But does it work in practice?
A growing body of literature suggests the answer is yes. In a 2019 consensus report published in the journal Diabetes Care, the authors write that carbohydrate reduction has “the most evidence for reducing glycemia” in those with type 2 diabetes.
Some of the most compelling evidence comes from a company called Virta Health. Researchers from Virta Health rounded up 218 type 2 diabetics, placed them on a supervised keto diet for a full year, and published the results in the peer-reviewed journal Diabetes Therapy.
Here are some highlights from that 2018 study:
- Average weight loss was 30.4 pounds
- 60% of patients moved from “diabetic” to “prediabetic” or “normal” blood sugar (Average HbA1C declined from 7.6% to 6.3%)
- 94% of patients reduced or eliminated insulin therapy
“That’s nuts, Robb! But what happened to the 87 patients in standard care that served as a control group?” Their biomarkers did not improve.
Concerns About Keto For Type 2 Diabetes
The keto diet is a promising diabetes therapy, but it’s not without its downsides. Here are the big ones.
#1: Medication risks
Diabetes medications act to lower blood sugar. On a low-carb diet, a patient may—if not properly supervised—end up with a dangerous case of low blood sugar, or hypoglycemia.
Common Blood Sugar Medications
- GLP-1 receptor agonists
- SGLT2 inhibitors
Again, supervision is essential to avoid potentially fatal complications with these medicines.
Let’s face it: Keto is restrictive. It can be difficult to give up all your favorite carbs, especially in social situations.
For some, it’s so difficult that many people just won’t do it. And if you can’t stick to a diet, you won’t get the results you’re looking for.
So, if the keto diet seems too extreme, consider a whole foods Paleo approach instead. Eating whole foods—and not too much of them—is most of the battle anyway.
#3: Clinicians Are Skeptical
Don’t count on finding a keto-attuned doctor within 20 miles of your house. They’re out there, but they’re still rare birds.
One option is to skip keto and pursue a Paleo-type approach, assuming you’re not Paleo already. To avoid knee-jerk judgments from your doc, just explain it as a “whole foods diet adequate in protein, carbs mainly from low glycemic sources, and the preponderance of fats from monounsaturated sources.”
If you spin that by your Doc, they’ll likely say “great!” But if you say “I’m going paleo!” (which is built from precisely that formula) your Doc might just institutionalize you.
Another workaround is to virtually consult a keto-friendly clinician. With the benefit of telehealth technology, they can guide you from afar, no facetime needed.
The important thing is to find someone qualified to manage your care. If keto sounds like a good way to help manage your type 2 diabetes, get help so you can do it safely. Don’t go it alone.