Starting low carb or keto with diabetes medications
So you have diabetes and you want to try a low-carb or keto diet? Congratulations! It may be the single best thing you could ever do for your health. It can start to reverse your type 2 diabetes, and dramatically increase your blood sugar control with type 1 diabetes.
However, you need to know what you are doing. Once you start eating low carb you may instantly have to lower any insulin doses, a lot.
Avoiding the carbohydrates that raise your blood sugar decreases your need for medication to lower it. Taking the same dose of insulin as you did prior to adopting a low-carb diet might result in low blood sugar, something that can potentially become dangerous.
You need to test your blood sugar frequently when starting this diet and adapt (lower) your medication. This should ideally be done with the assistance of a knowledgeable physician.
No drugs
If you have diabetes and you’re treated either by diet alone or just with Metformin there is very low risk from low blood sugar on low carb. You can get started right away.
Insulin
As a general guide you may need to lower your doses by 30-50% or more when starting a strict low-carb diet.
Unfortunately there’s no way to know the doses required in advance. You’ll have to test your blood sugar frequently and adapt (lower) insulin doses. This should be done with the assistance of a knowledgeable physician.
Note that as a general rule it’s easier to err on the low side, and if your blood glucose goes a bit high you can take more insulin later if needed. That’s OK. If instead you overdose and get low sugar that is potentially far more dangerous. You’ll also have to quickly eat or drink more carbohydrates, and that obviously reduces the effect of the low-carb diet.
Insulin in type 1 diabetes
The advice on insulin above generally applies to type 1 diabetes too. A low-carb, high-fat diet can be fantastic for empowering people with type 1 diabetes to get steady blood sugars. It results in much fewer and milder highs or hypos (when insulin doses are adapted).
If you get regular hypos you should consider lowering your insulin.
One word of warning though: A strict low carb diet results in ketosis, a normal physiological state. A very strict low-carb diet that also restricts protein to moderate amounts can result in quite high, but still physiological (in other words, safe), ketone levels (e.g. 1.5 mmol/L, but sometimes as high as 4).
This is fine for healthy people, but in type 1 diabetes this means you’re uncomfortably close to ketoacidosis (usually at least 10-15 mmol/L). All that’s needed then is forgetting an insulin shot or two, or an insulin pump malfunction, and you might end up very sick in the hospital.
Thus it’s probably best in type 1 diabetes to try a more moderate low-carb diet, with a minimum of around 50 grams of carbs a day, so that you stay out of deeper ketosis (>1.5 mmol/L).
Do not do a strict low-carb diet (below 20 grams a day) unless you’re certain of how to handle this risk. Adding for example a fruit or two a day to it is probably wise, if you have type 1 diabetes. Just to be safe.
It’s also important to remember that while people with type 2 diabetes can relatively often reverse their disease enough to stop taking insulin injections entirely, someone with type 1 diabetes will always need to replace the insulin they lack.
With that said, a low-carb diet can have fantastic results for people with type 1 diabetes:
Insulin-releasing pills
Some pills for type 2 diabetes work by releasing more insulin in the pancreas. These can also result in low blood sugar on a low-carb diet, even if the risk is slightly smaller than with injected insulin.
These pills are called sulfonylureas and include glipizide, glibenclamide and glyburide, etc.
You may need to reduce the dose or stop these drugs on a low-carb diet, as you may rapidly become too healthy for them. Discuss it with your doctor in advance.
Metformin
Metformin tablets can be safely taken on a low-carb diet. There’s a very low risk of low blood sugar if you’re only on Metformin.
GLP-1 agonists (e.g. Victoza) and DPP-4 inhibitors (e.g. Januvia)
These drugs should rarely lead to low blood sugar on a low-carb diet by themselves. But be observant, check your blood sugar often and discuss it with your doctor as needed.
SGLT2 inhibitors (e.g. Farxiga, Jardiance, Invokana)
These drugs1 are a good way to treat type 2 diabetes, but as a known side effect they increase the risk of a dangerous condition called ketoacidosis. It’s likely that this side effect could become more common on a strict low-carb diet. Proceed with caution and discuss it with your doctor.
It’s worth noting that when ketoacidosis occurs while taking SGLT2 inhibitors, blood glucose is not necessarily high, making it harder to detect.
If you get symptoms of ketoacidosis: extreme thirst, nausea, vomiting, stomach pain, confusion etc. you should stop the medication, eat carbs and contact a doctor immediately.
Learn more
Top diabetes videos
More
A keto (strict low-carb) diet for beginners
Low carb for doctors
Are you a doctor or do you know one? Here’s our low carb for doctors resource, with information on how to safely handle medications on a low-carb diet:
For more brand names and information check out the Wikipedia page about this class of drugs. ↩
83 comments
Dr Bernstein is a type 1.... The last half of the book are recipes, from appetizers to dessert...
https://pat.libreview.com/
I recommend this meter, I've been on mine for about 60 days. It can help point out issues as it is monitoring all the time.
https://www.ketoconnect.net/
some of the best keto recipes I've found!
Read, a lot! You'll need to determine what works best for you.
I'm not sponsored by any of the above, just a type 2, diagnosed Dec 2017.
I've had T2 for many years, probably due to meals that were mostly carbs in combination with no exercise. I turned that around with good workouts starting in 2010 (with a 2-year break to recover from Stage IV rectal cancer).
So I'm currently on 2000 mg of metformin a day (1000mg bid), and returned to a full ketogenic diet 7-20-18 (maybe 5-10 net grams of carb each day). My BGs are lowering already, but not quickly (morning BGs are around 170% of desired/normal). My BGs are high all day, but especially in the morning. I know I'll need time for the liver to clear out the glucagen and for my body fat to change type, and my insulin resistance to be repaired. I'll be patient.
My question is: what changes in my BG should I use to guide my reduction in metformin? I don't want to reduce either too quickly or too slowly. Of course, my doctor has no idea--he wants to put me on glipizide er, which may work at first but like metformin would eventually, keeping a high carbs diet, just make the diabetes worse.
Hoping for some very specific advice, if possible. Otherwise, I'll just use my intuition (guesswork).
No.
Little to no hypos and hypers, ability to have a flatline at normal human BGLs (around 4.6mmol/83), ease with sport management, confidence at work etc not to mention total happiness with my physique. Diabetes or not, I'd stay low-carb for long-term health effects anyway.
Also, my diabetes honeymoon is happily ongoing and I remain on extremely low doses of insulin. I'll of course never go without insulin again (aside from random spots where I seem to have to go off it temporarily) but low carb directly correlates to the size of my long-acting dose. Less insulin = less anxiety.
*Also, probably LCHP not LCHF, so I have moderately low ketones. (.3-.7mmol).
I have been on low carb diet for almost 2 years and my blood sugar is great all day and all night except for my fasting BG which stayed elevated..due to , I am told, Fatty liver & the “Dawn Phenomenon “. My doctor kept me on the metformin only to treat my fasting BG ...however, it did not do anything for it.. I finally changed my insurance and started seeing a new Endocronologist who put me on Victoza and I am seeing some improvement but not fast enough and only on the days that I am taking it... if it weren’t for my fasting numbers I would have been off my medications and I am wondering if staying on Victoza will resolve my high fasting blood sugar & Insulin Resistance.
https://youtu.be/UQhkk3Ch8BY
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> 2.- En la dieta cetogénica, es verdad que cuando se agota la glucosa, se obtiene la energía (antes de utilizar las reservas de grasas) de los músculos y de los huesos, produciendo perdida de masa muscular y osteoporosis?
>
> 3.- En personas con diabetes tipo II, una dieta cetogenica, puede llegar a producir un "bajón" de azúcar en sangre, muy peligroso para la vida?
Hope this helps
I have a cgm, and i also check my sugar a lot. But what can i do if i get low blood sugar? I know it will take time to adjust my insulin pump to the proper basals. But what do others do for lows?
I am looking to start this low carb diet thing, and just gaining some info!
Thanks,
Cam
Also, must my carb content stay under 5 carbs for EACH meal to stay in Ketosis?Can I eat any amount of fat or is there a limit?
Thanks for any help on this. Kim
https://www.dietdoctor.com/low-carb/get-started
I keep hearing about this. I, like others here, am about to start this keto lifestyle, am T2 for two years or so. 1000 metformin/day.
What is the best way to start? What foods are the best to start off with?
I guess thats what I want to know. I need to lose about 50-60 lbs...have highish blood sugar due to metformin apparently, and probably mainly because I take caffein pills due to low energy. I seriously need energy without the help of any caffein type things.
Any help will be greatly appreciated.
Thanks. Bev
https://www.dietdoctor.com/low-carb/keto
Many doctors use keto/lchf as part of the treatment for fatty liver - https://www.dietdoctor.com/groundbreaking-study-low-carb-effective-tr...