The CGM Blog

What You Need to Know Before Trying Popular Diets for Diabetes

When you’ve been diagnosed with diabetes, diet becomes a major part of your life as you begin your diabetes management journey. Along with exercise and other biological factors, what we eat plays an important role in regulating glucose levels in the body and our overall health.

While discussing diabetes management strategies with your healthcare provider, you might be wondering:

What is the best diet I should be on if I have diabetes?

There are many diet options out there that may have benefits for individuals living with diabetes and there isn’t a one-size-fits-all answer. Understanding the diet options available to you is a great first step and will help you bring the right questions to your doctor when it comes time to explore new changes to your self-care plan.

If you’re living with diabetes, you may have heard about the Mediterranean, keto, and paleo diets as possible ways to manage your blood sugar through diet. These diets are just a few examples of ways to approach your eating habits and following any one of them could be an effective way to manage weight and maintain overall health.^1,2,3

The Mediterranean, keto, and paleo diets all focus on whole foods—rather than processed or packaged options—and emphasize proteins, healthy fats, and fibre-rich vegetables as well as reduced carbohydrates. To figure out if any of these diet plans are right for you, it’s a good idea to learn a little more about their effect on the body. Speak with your doctor about how changes to your diet can best align with your preferences, unique needs, and treatment goals.

Will I need to make changes to my diabetes medications when starting a diet?

When deciding on any diet to help you manage your diabetes, your doctor should be your first stop in deciding what’s best for you. They will be able to give you further detail on a new diet regimen and recommend any changes to your insulin or other medications. If choosing a low carb diet, it’s especially important to discuss this with your doctor as some oral medications may cause hypoglycemia if taken with a low carb meal. Lastly, ask your doctor about side effects of your medications as some can cause weight gain. It’s important to stay informed and motivated as you’re putting your health first, that’s an accomplishment in itself!

The Mediterranean Diet: Focused on Whole, Plant-Based Foods

The Mediterranean diet rose in popularity in the 1950s when research emerged showing that heart disease wasn’t as common in people living around the Mediterranean Sea in places like Greece and Southern Italy.⁴ The diet is mostly plant-based and prioritizes whole grains, vegetables, fruits, nuts and seeds, as well as herbs and spices. Olive oil is the primary source of fat and there’s an emphasis on eating fish and poultry instead of red meat. Moderate amounts of dairy are also included in the diet.

The World Health Organization created the Mediterranean Diet Pyramid as a guide for which foods to eat. Additionally, Diabetes Canada has a Mediterranean diet meal plan that has examples of delicious options.

In terms of diabetes management, this diet has been shown to reduce A1C levels and improve glycemic control in those newly diagnosed with type 2 diabetes (T2D).² Studies also show that following the Mediterranean diet is linked to improved insulin levels and reduced insulin resistance in people living with T2D.² Additionally, sticking to the Mediterranean diet has been shown to reduce the risk of cardiovascular diseases.²

One of the unique features of the Mediterranean diet is a focus on leading an active lifestyle and regularly enjoying meals with friends and family.⁶ This can make mealtime more fun and help you stay connected to your support network. For people living with type 1 diabetes (T1D), one study showed that following the Mediterranean diet is linked to an enhanced quality of life.⁷

Here are a few things to keep in mind when following the Mediterranean diet:

The diet is fairly flexible in the foods you’re able to eat and you’ll need to determine portion sizes or calorie counts that will best support your glucose management.8
Drinking wine in moderation is also a part of the Mediterranean diet. Look into any interactions between any medications you’re taking and be aware of how alcohol changes your glucose levels to avoid hypoglycemia.⁹
Stay on top of your glucose levels to see how your food choices are affecting your body.

The Keto Diet: High in Protein & Healthy Fats

The ketogenic, or “keto” diet is a very low-carbohydrate diet that is typically high in healthy fats. You may have noticed that keto diets are a popular option for individuals looking to lose weight. This is because limiting carbohydrate intake forces the body to turn fat into molecules called ketone bodies, or simply “ketones,” and use these for energy instead of the glucose found in carbs.¹⁰ When there are more ketones present in the body, it’s called ketosis.

There is no strong evidence that a keto diet in particular makes a significant impact on glucose control in people living with diabetes.¹

However, studies show that reduced-carbohydrate diets in general can help people living with T2D manage their weight, potentially improving glucose control¹¹and may contribute to lowering A1C in people living with T1D in the short term.¹ Keep in mind that even if you eliminate carbs, you must continue to monitor your glucose levels and, most importantly, watch out for hypoglycemia.¹ Also note that low-carb keto diet affects individuals living with type 1 or type 2 diabetes very differently.

While a ketogenic diet can be a good option for some people living with T2D, researchers are still unsure about the safety of the diet for people living with T1D.¹¹ This is because people living with type 1 diabetes do not produce any insulin, which means that the body can’t get energy from glucose. When the body senses that it doesn’t have access to glucose, it turns on ketone production. If the body doesn’t have access to glucose over a sustained period of time and an excess of ketones are released into the blood, it can result in diabetic ketoacidosis, also known as DKA.¹²

Currently, there is no evidence that suggests that a low-carb diet or keto diet can delay or prevent the onset of type 1 or type 2 diabetes.

Here are a few things to keep in mind when following a ketogenic diet:

Eat a variety of protein- and fat-rich foods that can include fish, Greek-style yogurt, olives, and nuts and seeds.¹³
Drink plenty of water and other hydrating fluids to ensure that you have enough electrolytes such as sodium and magnesium.¹³
Continue to monitor glucose levels to be proactive about DKA and prevent hypoglycemia.¹³

The Paleo Diet: Packed with Protein & Organic Veggies

Like the keto diet, the palaeolithic, or “paleo,” diet is a low-carbohydrate diet. The concept of the diet was inspired by what humans used to eat as hunter-gatherers, before the rise of farming. The diet prioritizes lean meats, fatty fish like salmon and tuna, fresh fruits and vegetables, and nuts and seeds. Some versions of the diet are strict about eating grass-fed or wild game meat. A hallmark of the paleo diet is the elimination of processed foods like wheat and oats, dairy products, and anything that contains refined sugar. Paleo also emphasizes eating local, organic, and non-GMO foods—keeping things as “natural” and eco-friendly as possible.

There’s debate about whether the paleo diet is an accurate reflection of what our prehistoric ancestors actually ate. Humans living in various parts of the world had access to very different foods, so it’s not likely that today’s paleo diet represents what all people ate pre-agriculture. Nonetheless, the paleo diet does encourage healthy food choices that may help with glucose management.

Studies have shown that when a low-carb diet, such as paleo, is combined with exercise, individuals have seen improvement in insulin sensitivity, glucose tolerance, and a reduction in inflammation.¹⁴ However, in comparison to other diets considered to be healthy in terms of glucose and insulin regulation, the paleo diet doesn’t offer any major differentiating benefits for people living with diabetes.^{15, 16} If the paleo diet suits your tastes and your doctor agrees that sticking to the foods associated with the diet will benefit you, then it may be worth trying.

Like the keto diet, the paleo diet is low in carbohydrates and sugars. If you choose to follow the paleo diet, make sure you’re eating enough carbs and sugar to maintain your blood glucose levels and avoid hypoglycemia.¹ Diabetic ketoacidosis is also a risk for people living with T1D who significantly reduce their carbohydrate intake.¹¹ Always take steps to ensure that your diet aligns with your treatment plan before changing your eating habits.

Here are a few things to keep in mind when following a paleo diet:

Keep an eye on how much fat you’re consuming, including healthy sources of fat like fish, lean meat, dairy, and even coconut oil. Eating too much can raise your cholesterol.¹⁷
Make sure you’re getting enough essential vitamins and minerals. Strict adherence to the paleo diet could lead to deficiencies in calcium and vitamin D.¹⁸
Monitor your glucose levels to limit the risk of developing DKA and prevent hypoglycemia.⁷

Start Small, Stay Curious

The Mediterranean, keto, and paleo diets can be effective for certain people living with diabetes, but it's important to remember that none of these is a one-size-fits-all solution. If you're interested in learning more about these diet options, talk to your healthcare provider to see if one of them might be a good fit for you.

If you decide to give it a try, start small and stay curious. Going on a new diet doesn't have to be a full-time job. In fact, you can start by adding healthy low-carb or Mediterranean-inspired meals to your regular diet and seeing how that goes. Whenever you make diet or lifestyle changes, it can be helpful to keep track of how your body feels day-to-day so you can look back and see if there have been positive or negative changes over time. This can help you communicate your experiences to your healthcare provider as you decide on the best course of action going forward.

An effective way to track the potential changes that come with new eating habits when following the Mediterranean, keto, or paleo diet is to use a continuous glucose monitoring (CGM) device like the Dexcom G6 CGM System. No matter which diet you choose, a CGM system can help you make decisions about what to eat in the moment, but also learn how your diet choices affect you after eating.

Dexcom G6 can help you understand how different foods affect your glucose levels and be proactive about any sudden changes.* Dexcom G6 works by measuring your body’s glucose levels and sends that data to a compatible smart device or receiver up to every 5 minutes, enabling you to view your glucose levels in real time. You can also easily share glucose data history with your healthcare provider through the Dexcom Clarity app and keep your loved ones in the loop with the Dexcom Share feature and Dexcom Follow app.^†

Need help with insurance coverage? Speak to our team of Account Specialists to explore your options.

Learn more about ways to lower your A1C that go beyond diet.

Read the blog post

* If your glucose alerts and readings from the G6 do not match symptoms or expectations, use a blood glucose meter to make diabetes treatment decisions.
† Separate Follow app and an internet connection required. Users should always confirm readings on the Dexcom G6 app or receiver before making treatment decisions.
‡ Back of upper arm wear is available for users 18 years and older.

1 Diabetes Canada. Diabetes Canada Position Statement on Low-Carbohydrate Diets for Adults With Diabetes: A Rapid Review. Canadian Journal of Diabetes. 2020;44(4):295-299. Accessed April 26, 2022. doi: 10.1016/j.jcjd.2020.04.001
2 Martín-Peláez S, et al. Mediterranean Diet Effects on Type 2 Diabetes Prevention, Disease Progression, and Related Mechanisms. A Review. Nutrients. 2020;12(8):2236. Published 2020 Jul 27. Accessed July 13, 2022. doi: 10.3390/nu12082236
3 Klonoff DC. The beneficial effects of a Paleolithic diet on type 2 diabetes and other risk factors for cardiovascular disease. J Diabetes Sci Technol. 2009;3(6):1229-1232. Published 2009 Nov 1. Accessed July 13, 2022. doi: 10.1177/193229680900300601
4 Mediterranean diet for heart health. Mayo Clinic. Updated July 23, 2021. Accessed June 29, 2022. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/mediterranean-diet/art-20047801
5 Estruch, R, et. al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet Supplemented with Extra-Virgin Olive Oil or Nuts. The New England Journal of Medicine. 2018; 378:e34. Accessed June 29, 2022. doi: 10.1056/NEJMoa1800389
6 Diet Review: Mediterranean Diet. Harvard School of Public Health. Updated December 2018. Accessed June 29, 2022. https://www.hsph.harvard.edu/nutritionsource/healthy-weight/diet-reviews/mediterranean-diet/
7 Granado-Casas M, Martin M, et. al.. The Mediterranean Diet is Associated with an Improved Quality of Life in Adults with Type 1 Diabetes. Nutrients. 2020; 12(1):131. Accessed June 30, 2022. doi: 10.3390/nu12010131
8 Fallabel, C. The Mediterranean Diet and Diabetes. Diabetes Strong. October 6, 2021. Accessed June 30, 2022. https://diabetesstrong.com/mediterranean-diet-diabetes/
9 Alcohol and Diabetes. American Diabetes Association. Accessed June 30, 2022. https://www.diabetes.org/healthy-living/medication-treatments/alcohol-diabetes
10 Masood, W, et. al. Ketogenic diet. StatPearls. Accessed March 31, 2022. https://www.ncbi.nlm.nih.gov/books/NBK499830/
11 Bolla et al. Low-carb and ketogenic diets in type 1 and type 2 diabetes. Nutrients. 2019;11(5): 962. doi: 10.3390/nu11050962
12 Ketones. Diabetes Education Online. Accessed March 31, 2022. https://dtc.ucsf.edu/types-of-diabetes/type1/understanding-type-1-diabetes/how-the-body-processes-sugar/ketones/
13 Buehler, L.A. et al.. Ketogenic diets in the management of type 1 diabetes: Safe or safety concern? Cleveland Clinic Journal of Medicine. 2021;88(10):547-555. Accessed April 26, 2022. doi: 10.3949/ccjm.88a.20121
14 Chen, C.N., et. al. Effects of Combined High-Protein Diet and Exercise Intervention on Cardiometabolic Health in Middle-Aged Obese Adults: A Randomized Controlled Trial. Frontiers in Cardiovascular Medicine. 2021;8. Accessed June 29, 2022. https://www.frontiersin.org/articles/10.3389/fcvm.2021.705282/full
15 Jamka M, et. al. The Effect of the Paleolithic Diet vs. Healthy Diets on Glucose and Insulin Homeostasis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Clin Med. 2020 Jan 21;9(2):296. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7073984/
16 Andrikopoulos, S. The Paleo diet and diabetes. Med J Aust. 2016; 205 (4): 151-152. Accessed June 30, 2022. doi: 10.5694/mja16.00347
17 The Skinny on Fats. The American Heart Association. Updated Nov 11, 2020. Accessed June 29, 2022. https://www.heart.org/en/health-topics/cholesterol/prevention-and-treatment-of-high-cholesterol-hyperlipidemia/the-skinny-on-fats
18 Paleo diet: What it is and why it's not for everyone. UC Davis Health. April 27, 2022. Accessed June 30, 2022. https://health.ucdavis.edu/blog/good-food/paleo-diet-what-it-is-and-why-its-not-for-everyone/2022/04