There are some things that people should not do on their own and one of them is to begin a very low carb (ketogenic) diet without first consulting with their doctor, especially if they take certain types of medication. Medical supervision is necessary before a person substantially decreases their carbohydrate intake if they are taking;
(1) insulin
(2) medication to lower blood glucose such as sodium glucose co-transporter 2 (SGLT2) medication including Invokana, Forxiga, Xigduo, Jardiance, etc.
(3) medication for blood pressure such as Ramipril, Lasix (furosemide), Lisinopril / ACE inhibitors, Atenolol / βeta receptor antagonists, etc.
(4) mental health medication such as antidepressants, medication for anxiety disorder, bipolar disorder (such as Lithium), and schizophrenia.
I don’t provide low carb or ketogenic services those taking insulin (either type 1 diabetes or type 2 diabetes) as I do not have CDE certification. I will provide services if a person is being overseen by their endocrinologist and do require a doctor’s letter. This is very important because clinical studies indicate that injected insulin levels need to be adjusted downward very soon after beginning a low carb or ketogenic diet and this needs be supervised.
Those taking medication for mental health conditions should consult with their psychiatrist and/or family practice physician before adopting a low carb or ketogenic diet as this may have an effect on the dosage of some types of medication, including mood stabilizing medications such as Lithium. (A recent article written by Psychiatrist Georgia Ede, MD related to a ketogenic diet appeared in Psychology Today and appears here.)
I advise people coming to me to implement a low carbohydrate or ketogenic lifestyle and taking medications to control their blood sugar, or blood pressure to first consult with their doctor before changing how they eat because blood sugar levels and blood pressure decreases fairly soon after adopting these diets and can have serious consequences if dosages of these medications are not monitored and adjusted downward (sometimes being discontinued entirely). For example, a sudden drop in blood pressure could result in people becoming dizzy or confused and could even result in injury to themselves or others if they ‘blacked out’ while walking or driving a car.
Some medications which lower blood sugar such as sodium glucose co-transporter 2 (SGLT2) medication including Invokana, Forxiga, Xigduo, Jardiance, etc. might result in life-threatening and even fatal cases of a very serious condition called “diabetic ketoacidosis (DKA)” even with no change in diet, but these risks can be increased for patients on a very low carbohydrate diet as the combination of the medication and diet may increase the amount of ketone production (see Health Canada’s Safety Review here).
Those with significant alcohol consumption who are taking these medications are at risk for DKA, so it is very important that if you drink alcohol on a regular basis and take these medications to tell your doctor. If you are taking any of these medications and come to me, I will ask you about your alcohol consumption because alcohol and these medications together could potentially result in this serious and potentially life-threatening condition.
People taking any of the above medications (or any medications for other conditions) should not adopt a low carb or ketogenic lifestyle on their own without first checking with their doctor.
Another thing that people should never do on their own is adjust the dosage of any of their prescribed medications without first discussing it with their doctor. The consequences of doing so can be very serious, even life-threatening. For example, people taking SGLT2 inhibitors such as Invokana or Jardiance who decrease their insulin dosage suddenly are at increased risk for DKA. This is very serious. Medication dosages and timing must be adjusted by a doctor.
Another condition, which is less common than DKA but is very serious, is Hyperosmolar Hyperglycemia State (HHS). It is life-threatening and has a much greater death rate than DKA, reaching up to 5-10%. It is most commonly seen in people with Type 2 Diabetes (T2D) who have some illness that results in reduced fluid intake, and they become seriously dehydrated. Being sick with an infection is one such situation where it is very important for you to see your doctor if you have T2D, so they can monitor you for HHS. You can read more about HHS here.
If you come to see me to adopt a low carb diet, I will work with you to coordinate dietary and lifestyle changes with your doctor, as they monitor your health and adjust the levels of prescribed medications. In more complex cases, I may ask for written consent to coordinate care with your doctor because, depending on those medications, your doctor may need to know in advance what level of carbohydrates you have been advised to eat so that they can monitor your health and make adjustments in your medication dosage.
Your health is important, and your diet and medications need to be coordinated and overseen by your doctor. The potential risks are too great to attempt to do this on your own.
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To your good health!
Joy
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Joy is a Registered Dietitian Nutritionist and owner of BetterByDesign Nutrition Ltd. She has a postgraduate degree in Human Nutrition, is a published mental health nutrition researcher, and has been supporting clients’ needs since 2008. Joy is licensed in BC, Alberta, and Ontario, and her areas of expertise range from routine health, chronic disease management, and digestive health to therapeutic diets. Joy is passionate about helping people feel better and believes that Nutrition is BetterByDesign©.