The facts on type-1 diabetes and diets

Why don’t I, as a diabetes dietitian, promote dieting for managing type-1 diabetes?

Well, as the sonnet goes, let me count the ways.

Hi Friends!

Today I want to talk about type-1 diabetes and diets – specifically, why I don’t endorse them for my BC-based practice.

The facts on type-1 diabetes and diets are, well, there really are no facts.

Or, at the maximum, there’s very little facts to support dieting with T1D.

Yet, this has been a hot topic in the T1D world for years.

I have been asked countless times for advice on how to implement one restrictive diet or another into a T1D nutrition plan.

I’ve also been asked to present on various diets and T1D.

Let me be clear: I am always willing to have that conversation.

But, unlike Google, and unlike your friend who may have had success with a certain diet, I will clearly lay out the evidence-based negatives along with those potential positives.

And, I will encourage you to pursue another direction – one that focuses more on balance and less on restriction and rules.


There is clear evidence that shows that restrictive diets do not work in the long run for optimal T1D health.

And oftentimes, they can be counterintuitive.

Balanced eating is sustainable eating

The Diets:

When I say restrictive, I’m talking keto, low carb, intermittent fasting – pretty much, I’m talking any kind of food directive that has rules attached. But let’s focus on these three main ones.

  • Keto Diet: involves consuming minimal carbohydrates (less than 50 grams per day), moderate protein, and high fat for the purpose of burning fat and utilizing ketone bodies for energy, instead of glucose.
  • Low Carb Diet: involves consuming minimal carbohydrates with the intent of minimizing blood sugar fluctuations and insulin requirements.
  • Intermittent fasting: involves either every other day fasting, one very low-calorie meal per day fasting, or time-restricted eating where you have a specific window in the day that you can eat, such as a 4 hour, 8 hour, or 10 hour window. All other hours are no limits for food.

If you Google any of these diets and type-1 diabetes, you will find pages of positive reports, including proclamations of optimal blood sugar management, weight loss, greater focus, lower appetite, etc., etc..

Which sounds great, right?

But the thing to note here is that most of these reports are anecdotal with little to no broad-spectrum evidence backing them.

And that’s a problem.

We need to stop food restriction and food rules for type-1 diabetes management. Diets don't work.

The Evidence: Keto and Low-Carb

So, what does the evidence say?

Keto and low-carb diets have been linked to poor heart health, nutritional deficiencies, impaired metabolism, constipation, and kidney stones to name a few.

They’ve also been proven to not be sustainable for most people.

Weight loss, resulting from these diets, often comes back within a 5-year period, and often with a weight greater than what was initially lost.

Our bodies are not dumb.

When we significantly deprive our bodies of nutrition, there are mechanisms in place for the body to restore that nutrition as soon as it’s reintroduced again – and oftentimes in excess.

Yet, if we eat a balance of foods from all food groups, including treats once in awhile, and if we are mindful of portions, we are less likely to experience those weight and blood glucose fluctuations.

Balanced eating is sustainable, but keto and low-carb are not.

Type-1 diabetes and diets: enjoying food is better than avoiding food

The Evidence: Time Restricted Eating

But what about time-restricted eating?

This is the diet that “allows” you to eat within a specific time period, anywhere from 4 hours to 10 hours.

Right now, it is likely the most popular diet of choice for diabetes management – heavily promoted in media, in T1D circles, and even by healthcare professionals.

Yet, there is NOT a lot of evidence period on T1D and intermittent fasting.

There are no clear medical guidelines.

Recommendations are anecdotal at best.

There have only been a handful of studies conducted with a diabetes population, mostly type-2.

Most studies have been on rodents – not humans.

Of the human studies, they are short studies with small population sizes.

And the results are not significant related to improving HbA1c and daily blood glucose management.

Of all the studies conducted, there have been challenges with low blood sugars when on insulin. One study showed a 1/3 increase in hypoglycemic events per week.

The research is limited and the evidence is lacking.

And no matter which way you look at this, it is a diet and diets are not sustainable – there is clear evidence proving that!

All foods can be good foods in type-1 diabetes management

Recommendation: Interview Yourself

If you’re interested in starting a diet with T1D, you really do need to look into yourself and clearly understand your reasons for wanting this, and how it might impact your overall life.

You should ask yourself:

  • How do you think this diet will benefit you?
  • What is your purpose for starting this diet?
  • Is it for weight loss?
  • Is it for blood sugar control?
  • Can you see yourself doing this for years?
  • Is it a short-term intervention?
  • If it’s short-term, what happens when you stop?
  • Are you an athlete – how will this diet impact your performance goals?
  • Are you susceptible to low blood sugars – how will you mitigate that with this diet?
  • Do you enjoy social eating – how would that be impacted?
  • What happens when you’re hungry?
  • How will you feel if you miss a day of the diet?

Managing type-1 diabetes with balanced eating is more sustainable than managing with diets

The Bottom Line:

We need to be clear of our reasons for wanting to start a diet.

And we need to understand the potential negative implications of doing so.

We also need to recognize that balanced living can produce the same results, albeit over a longer period of time, but with long-term success, and a heck of a lot more enjoyment!

As people with type-1 diabetes, we have long been preached on food restriction.

There is a significant percentage of our population that suffers from eating disorders as a result.

It’s time to ditch the food rules and learn a more sustainable way of managing T1D with nutrition, insulin, and exercise.

4 thoughts on “The facts on type-1 diabetes and diets”

  1. I gotta say, I love, love, LOVE this post. I’ve been telling people for years, Diabetics and non-Diabetics alike, that restrictive dieting is not a good idea. I always learn something from your posts, keep ‘em coming.

    1. Hi Katie,very interesting blog and thanks for posting 🙂

      My 20 year old son was diagnosed with Type 1 a couple of years ago, he tends to stick to a lower carb diet purely because he finds it keeps his levels steady and he’s much happier, way less stress!

      Initially it was suggested by one of his health professionals not long after diagnosis and seems to work for him.

      He’s put on a stone and a half of muscle through gym going and eating this way and believes this is how he wants to continue going forward, saying that though,I know he doesn’t think of it as dieting ,more eating healthily.

      Look forward to reading future blogs.

      1. Hi Janet,

        Thank you so much for sharing. There is no doubt that for some people it does work and they’re able to manage it over the longterm. And I think it’s fantastic if that’s enjoyable for them.

        However, for the majority of people it has been shown to not be sustainable. I’ve worked with many people who have gone a very low carb route and maintained it for several years, but over time they ended up over restricting foods / avoiding foods for the fear of blood sugar fluctuations, and it developed into disordered eating, impaired relationship with food, and mental health concerns.

    2. Thanks – as always – Shawn. for your feedback. I really do appreciate it. And I love the advocacy that you’re doing in the community too!

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