Healthy Food Guide looks at the upsides and downsides of the ketogenic diet for managing type-2 diabetes
Q I have heard that the keto diet is great for reversing my type-2 pre-diabetes. But you guys don’t seem to recommend it. What’s the story?
A The keto diet has been around a long time, since the 1920s, and certainly does have its place. Like many restrictive diets, it can be a quick way to lose weight. And dietary changes coupled with increased physical activity are among the best lifestyle modifications for type-2 diabetes and prediabetes treatment or management.
A common issue is whether you can keep up your dietary changes in the long term. With keto being so restrictive, this can be hard. Also, the science is emerging as to what other effects on your health it may have. We have written about it several times, see: Is keto or fasting better for weight loss?, Getting enough fibre on a keto diet and Keto diet may be best in small doses.
The science-backed approach to type-2 diabetes
At Healthy Food Guide our approach is to follow the science and collective body of research on issues, rather than a current trend. The science shows that lower-carb diets can have positive results for people with type-2 diabetes, in the short term, but those benefits appear to even out, over time, when compared with other dietary interventions.
Having meals based on the ‘ideal plate’ – quarter of the meal protein, quarter carbohydrate (ideally ones that burn slower/have a lower glycaemic index) and half non-starchy vegetables – is the best way to go. See our Diabetes Toolkit and diabetes-friendly recipes for examples.
Our approach is that any dietary plan needs to be enjoyable, healthy and sustainable, so you have no trouble keeping going with it. That means if a keto diet works for you and you can keep to it long term, to achieve your goals, then it may well help you. But it’s good to remember that the science also suggests highly restrictive diets seldom work in the long run and can lead to yo-yo dieting patterns and weight gain, over time.
Upsides to keto
- If followed strictly, a keto diet will likely result in weight loss and improvement in blood sugar and blood fat levels for people with type- 2 diabetes
- Lots of rules, so you know exactly what to do
- Can be low in processed foods, although some are allowed.
Downsides to keto
- May be hard to keep up with the strict limitations in real life
- It’s extremely low in carbohydrates – an important source of fuel for your brain and body
- It’s low in fibre – which is important for gut and bowel health. A good intake of fibre is associated with lower all-cause mortality in people with diabetes
- Can lead to fuzzy brain (keto brain), due to a deficit of carbs
- Can lead to ketone smell
- Following a keto diet may mean you have to change the amount of insulin or sulphonylureas (such as glibenclamide, glipizide and gliclizide) you need. If you don’t change your medication amount you may increase the risk of low blood sugar levels. Always talk to your health professional first.
- If you want to try keto, do it for a short timeframe, then move on to a fibre-rich Mediterranean-style diet high in fresh fruits, vegetables and whole grains
- Make small changes that you find enjoyable and sustainable, eg, replace processed snacks with fruit and unsweetened yoghurt
- Start some form of exercise that you actually enjoy, so you can do it every day. It can be as simple as a walk around the block
- Keep in touch with your health professional and monitor your medication.
Article sources and references
- Bansal N. Prediabetes diagnosis and treatment: A review. World J Diabetes. 2015;6(2):296-303. doi:10.4239/wjd.v6.i2.296https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4360422/
- Sami W, Ansari T, Butt NS, Hamid MRA. Effect of diet on type 2 diabetes mellitus: A review. Int J Health Sci (Qassim). 2017;11(2):65-71https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5426415/
- Dyson P. Low Carbohydrate Diets and Type 2 Diabetes: What is the Latest Evidence? [published correction appears in Diabetes Ther. 2015 Dec;6(4):649]. Diabetes Ther. 2015;6(4):411-424. doi:10.1007/s13300-015-0136-9https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4674467/
- Choi, Y. J., Jeon, S. M., & Shin, S. (2020). Impact of a ketogenic diet on metabolic parameters in patients with obesity or overweight and with or without type 2 diabetes: a meta-analysis of randomized controlled trials. Nutrients, 12(7), 2005https://pubmed.ncbi.nlm.nih.gov/32640608/