The Ketogenic Diet For Blood Sugar Management (By Andy The RD)

The Ketogenic Diet For Blood Sugar Management (By Andy The RD)

This guest post was written by Andy De Santis (Andy the RD).

One of the primary purposes of blogging for health professionals is to educate large groups of people on topics that we deem pertinent.

For myself personally, the easiest way for me to determine which topics are most pertinent is simply by being observant in practice.

In other words, I try to write content that reflects the issues I see on a daily basis in practice because I know they more than likely are impacting the health and decision making of a wide array of people in the general public.

Today, and not for the first time, the object of my affections happens to be the ketogenic diet.

More specifically, the idea that individuals newly diagnosed with pre-diabetes or elevated blood sugar levels (as per a physician) are enamoured by the ketogenic diet as a fail-safe to regain control of their blood sugar management.

So today, in a very special guest post I am writing to be featured on the site of my long-time student blogger and now full blown dietitian Leigh, I’ve decided to re-visit this very hot topic.

The Ketogenic Diet And Blood Sugar Management

If you’ve been newly diagnosed with blood sugar management concerns (whether that be pre-diabetes, type 2 or otherwise), is dropping the carbs and jumping straight to the ketogenic diet your best course of action?

My professional observations are starting to suggest to me that more and more people are starting to believe this to be the case.

The goal of today’s article will be to kickstart the conversation on this increasingly relevant topic.

Before we go any further, I must state that today’s article is not meant to pass judgment on those who may opt to take the ketogenic route.

There is obviously a great deal of pressure associated with a diagnosis relating to one’s blood sugar levels ( or any other health malady for that matter).

In combination with the absolute endless stream of information online ( reputable and otherwise) it can be very challenging to make informed decisions about the appropriate course of action.


Ketogenic Diet – The Most Polarizing Diet Ever?

For the vast majority of health professionals (and most people generally) a dietary pattern that essentially completely excludes carbs lacks appeal and long-term practicality.

It’s for this reason that the ketogenic diet tends to elicit polarizing responses depending on who you ask about it.

 If you happen to ask the US News And World Report, they rank the ketogenic diet as the worst diet on their 2018 list of best diets ( note: I’m not saying that it necessarily deserves that ranking).

If you ask the forum members at* or certain individuals who may be heavily invested in the science or study of the diet, they might have something different to say.  

*Fictitious website – I had to!


Dietary Guidance For Diabetes

As a former employee, I always like to refer to Diabetes Canada Practice Guidelines when it comes to insights into best practice blood sugar management approaches, because I know how much effort and expertise goes into putting them together.

Some highlights from the 2018 guidelines on diabetes management best practices:

- Replacing high GI carbohydrates with low GI carbohydrates

- Flexible macronutrient distribution (within generally recommended levels AKA not 5%)

- Consistency in spacing, intake and regularity of carbohydrates

- A variety of dietary patterns can support the above ( keto not being one on the list)

The big one though:

People with diabetes should be encouraged to choose the dietary pattern that best aligns with their values, preferences and treatment goals, allowing them to achieve the greatest adherence over the long term.

Despite the other points, I do not underestimate or undervalue this last one.

Personal choice is very important, which is why no supportive health professional should necessarily be arbitrarily dismissing a client’s preferred dietary pattern, even if it trends to ketogenic.

To be fair as well to ketogenic diet proponents, given the emerging popularity of very low carbohydrate ketogenic diets, they aren’t really discussed super extensively in the latest practice guidelines.

Part of that is due to lack of evidence I’m sure, none the less it is not a topic to be avoided any longer.


Diabetes Canada Guidelines Vs Keto Diet – Round II

There are some other key areas of evidence in the guidelines that support good blood sugar control that also do not align with ketogenic diet guidelines.

These include:

1. Consumption of Pulses  

Due to their carbohydrate content pulses ( lentils, chickpeas etc*) are generally excluded or impossible to incorporate in any robust quantity into a truly ketogenic dietary pattern.  

*Dietary pulses, the dried seeds of nonoil seed legumes, include beans, peas, chickpeas, and lentils. This taxonomy does not include the oil-seed legumes (soy, peanuts) or fresh legumes (peas, beans). 

Something to consider though:

In people living with type 2 diabetes, individuals who swapped pulses for red meat enjoyed reductions to fasting blood glucose and insulin levels as well as to triglycerides and cholesterol.

Further reviews of studies using people with diets high in dietary pulses found that they are associated with improved fasting BG and A1C.

So we have here a big point of contention given that this group of foods is essentially excluded from a ketogenic diet, yet proven so effective for blood glucose management.

2. Fruits & Vegetables

Although lower carbohydrate veggies such as leafy greens are obviously heavily encouraged in a strongly patterned ketogenic diet, there is little room for starchy vegetables or fruit.

For the record, both starchy vegetables ( ie: sweet potatoes) and fruit ( ie: )  are rich in soluble fibre, which is known to be an effective tool in blood sugar management.

Although people often incorrectly assume the sugars in fruit are detrimental in diabetes management, incorporating fruit into the diet of people with type 2 diabetes has been shown to improve A1C over an extended period of time.

People with diabetes who eat at least 3 fruit servings a day also tend to have a decreased risk of cardiovascular disease.

So obviously we have another issue when it comes to fruit avoidance!


3. Overall Dietary Pattern

Diabetes Canada suggests there is evidence of a beneficial effect of the following diets when it comes to blood glucose management:

- Mediterranean


- Vegan/vegetarian

-  Any patterns which emphasize pulses, fruits, vegetables, nuts and other low GI foods.

So clearly the ketogenic diet does not explicitly appear on that list, although technically a good ketogenic diet would be rich in nuts and vegetables so that’s something.


In Support Of Keto/Low-Carb

It may have seemed like it thus far, but I promise that the goal of today’s article was not to trash the ketogenic diet.

Rather to simply offer some specific and objective evidence as it relates to the ketogenic diet’s utility in blood sugar management.

Let’s look at the positives:

A 2005 study out of the London Journal Of Nutrition & Metabolism found a ketogenic diet to be effective in blood sugar management in individuals with type 2 diabetes, even leading to discontinuation of medication. This was a single-arm study ( no controls) so there is no suggestion of superiority of this approach over a more balanced approach over the 16 week study duration.

In a 2008 follow up to the aforementioned study,  groups were randomized to either a ketogenic or low GI diet. Both groups experienced improvements in all key categories ( fasting blood sugar, A1C, medication reduction and blood lipids) but the effect was found to be significantly greater in the ketogenic group. There were methodological limitations in the study ( ie: lack of blinding) but the results remain noteworthy.

In a long-term study looking at a “low carb Mediterranean diet” found it to be superior to more traditional diabetes management approaches, perhaps offering support for the idea that a “best of both worlds” approach exists for those wanting to reconcile lower carbohydrate eating with more well proven and studied dietary patterns.

Even with the evidence outlined above, the totality of what is available in the human literature is probably still best described by the following quote from a 2015 Diabetes Therapy Paper:

Recent studies suggest that low carbohydrate diets appear to be safe and effective over the short term, but show no statistical differences from control diets with higher carbohydrate content and cannot be recommended as the default treatment for people with type 2 diabetes.


Still Want To Do Keto? – Talk To A Professional

Personal choice and autonomy are incredibly important in choosing a dietary pattern.

Many people you know may be enjoying their best health on a ketogenic diet, and you may want to give it a shot because it resonates with you.

Today’s article hopefully offered a balanced discussion of a sampling of the available human evidence in this increasingly popular and controversial subject area.

As I would suggest with anyone trying a dietary pattern involving restriction ( including new vegans or vegetarians!) it is always best to seek advice of a professional well-versed in your area of concern, especially  if you are uncertain how to carry out the pattern in the best possible way.

Using the ketogenic diet as a first line blood glucose management strategy certainly poses challenges and thus nutritional guidance from a dietitian can help optimize your nutritional status even in the face of self-imposed & significant restrictions to your diet.

All that being said, I hope you enjoyed today’s article.

If you found it useful, please share it widely to help support Leigh’s new and growing blog.

She has been a great blog partner over the years and is growing into a great dietitian!

Until next time,

Andy De Santis

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Dreamy Hot Chocolate

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