Low Carb Ketogenic Diet For Type 1 Diabetes - Blog Post 55 July 2018

This is a monthly update on my glycemic management of type 1 diabetes (T1DM) using Humalog and Lantus insulin injections with resistance exercise and a low carb ketogenic diet as described in my book, The Ketogenic Diet for Type 1 Diabetes also available on Amazon in print. My other book, Conquer Type 2 Diabetes with a Ketogenic Diet, is also available on Amazon in print. See below.

Although glycemic management in T1DM will always be challenging, the low carb ketogenic whole-food diet definitely improves it by reducing average blood glucose (BG) and variations in BG as well as insulin requirements. Those with T1DM who also have insulin resistance, called double diabetes, can reverse their insulin resistance with a low carb ketogenic diet, exercise, and other lifestyle changes. The low carbohydrate ketogenic whole-food diet directly improves both insulin resistance and endogenous hyperinsulinemia in T2DM and exogenous insulin requirements in T1DM (i.e. reduced insulin doses).

July 2018 was the fifth full month of taking metformin at a dose of 2000 mg/day (started that dose on Feb. 15, 2018). I am tolerating it without any side effects. As you may know metformin is the first-line medication for T2DM, but can also be useful for those with T1DM who also have insulin resistance. Although I do not have any signs of insulin resistance (excess body fat, increased waist circumference, hypertriglyceridemia, low HDL-C, high blood pressure), I was interested to see if my insulin requirements could be further reduced by taking metformin.  Metformin acts on the liver to reduce glucose production by suppressing both gluconeogenesis and glycogenolysis. I think this may be useful for those with T1DM on a low carbohydrate diet because the reduction in dietary carbohydrate reduces insulin requirements which in turn stimulates glucagon secretion by the alpha cells in the pancreas which in turn increases glucose production by the liver. This increase in glucose production occurs primarily from increased gluconeogenesis, but also some increase in glycogenolysis is suggested in some studies. In addition, metformin stimulates muscle uptake of glucose independent of insulin.

At this point in time, I am convinced that metformin is having a beneficial effect on my diabetes control via lower insulin doses. This is not so much based on the insulin doses per se because they have not changed much since Feb. 2018 when I started taking metformin. However, I normally take 1,000 mg before breakfast and dinner and on several occasions (about 10) when I forgot to take it, my post-meal BG was significantly higher than usual. There were no instances of the post-meal BG not being elevated when I forgot to take it either. My plan is to keep taking it indefinitely. Although I have not had an increase in hypoglycemia since starting metformin, there is a possibility that metformin could increase the incidence and severity of hypoglycemia while on a ketogenic diet, so caution should be exercised. A possible mechanism for this is the fact that gluconeogenesis plays a more important role in maintaining BG in those on a ketogenic diet than on a balanced macronutrient diet. If metformin reduces gluconeogenesis, then hypoglycemia could result if insulin doses are not appropriately reduced. 

Glycemic Results For July 2018

My July 2018 glycemic results were significantly improved compared to previous time periods and I did reach my desired BG goal of >70% time spent with a BG value between 61 and 110 mg/dl. I had less hypoglycemia this month with no symptoms of hypoglycemia. Below are my mean BG values, mean insulin doses, and BG frequency distribution for July 2018 compared to previous time periods. The predicted HbA1c uses the formula: AUC mean BG plus 88.55 divided by 33.298. This formula is the least squares fit using my own personal mean BG versus measured HbA1c over many years. My particular HbA1c values are higher than many other individuals with the same mean BG. This is referred to as being a “high glycator.”

As discussed previously, exogenous insulin cannot mimic normal insulin secretion, so persons with T1DM should not expect to have truly normal BG values at all times. They just need to be low enough to prevent long-term complications and not so low as to cause unpleasant hypoglycemic symptoms or less common, yet more dangerous, consequences including brain damage, seizure, injury, coma, or death. I have set my target BG range at 61-110 mg/dl because values in this range are not likely to lead to harm or complications of T1DM. Your target BG range should be determined with your physician because one size does not fit all. Normal BG is 96 ± 12 mg/dl (mean ± standard deviation (SD)) and coefficient of variation is 13% which is the weighted mean from two studies of continuous glucose monitoring in healthy subjects (see references at the end). The standard deviation and coefficient of variation are measures of BG variability which I believe are important in T1DM. Clinical outcomes in T1DM (i.e. microvascular and macrovascular complications) have only been documented to correlate with measures of mean BG, particularly HbA1c. This does not mean that BG variability is not important, but it just has not been documented to correlate with outcomes and complications of T1DM. Achieving a normal standard deviation or coefficient of variation in T1DM would be difficult, if not impossible, with current exogenous insulin therapy (injected or pumped). Monitoring the standard deviation and/or coefficient of variation and finding ways to improve them to the best of one’s ability is desirable in my opinion. Following a low carb whole-food ketogenic diet is one such method of reducing BG variability, mean BG, insulin doses, and hypoglycemia. A ketogenic diet may also provide an alternate or additional brain fuel in the form of ketones to protect the brain when BG does go low. The alternative energy that ketones supply to the brain may prevent or blunt the sympathoadrenal response to hypoglycemia which in turn reduces or eliminates the symptoms of and harm from hypoglycemia. This hypothesis needs to be tested before it can be stated as fact. Having mild asymptomatic hypoglycemia adapts the brain to lower BG and reduces the symptoms of mild hypoglycemia and potentially the harm from hypoglycemia due to lack of activation of the sympathetic nervous system by reducing sympathoadrenal-induced fatal cardiac arrhythmia (see references at the end).

Below are my BG readings along with the Humalog (rapid-acting insulin) doses in July 2018. I adjust the breakfast (blue circles), post-workout lunch (black circles), and dinner (purple circles) meal-time doses based on the pre-meal BG reading and take extra correction Humalog doses (red circles) for high BG readings as needed. I continued my previous pattern of higher BG readings after weightlifting which I correct with my lunch-time Humalog dose.

The table below shows the BG variability results for current and previous time periods. The percentiles (10th, 25th, 75th, 90th) on the right show the spread of the BG readings about the median. The interquartile range, the difference between the 75th and 25th percentiles, is a measure of BG variability. In the middle of the table are the %Time in three BG ranges: %Time BG < 61 mg/dl (hypo) and the mean BG during that time, then %Time BG 61-110 mg/dl (target) and the mean BG during that time, and %Time BG > 110 mg/dl (hyper) and the mean BG during that time. Both the %Time with hypoglycemia and hyperglycemia are probably overestimates because they do not account for the corrections with glucose tablets for hypoglycemia or rapid-acting insulin (Humalog) for hyperglycemia. Measuring my BG more frequently than 5 times per day or using an accurate CGM would result in a more accurate estimate.

The total basal (Lantus), meal-time rapid-acting (Humalog), and total insulin doses along with the BG readings and are shown in the graphs below for July 2018. You can see I had to gradually decrease the basal insulin (Lantus) dose during July due to either low fasting BG or a significant reduction in BG from bedtime to morning. Overall, the total daily insulin dose decreased only slightly.

The daily insulin dose totals for 2018 are shown in the graph below. You can see a reduction in insulin doses since the peak at the beginning of January 2018 followed  by a stabilization in the total daily insulin dose. The measures I have taken to reduce this variation in insulin dose have included keeping meals and exercise as constant as possible and adding metformin to suppress liver glucose production. Specifically, I try to keep all meals constant in terms of portion size, macronutrient composition and timing of my meals. In addition, I try to keep exercise constant including frequency (daily), type (the type of weightlifting exercises, mainly compound movements), intensity (gradually increasing weight over time as tolerated), and volume (repetitions). That said, keeping exercise intensity constant from day to day is quite difficult.

The graph below illustrates the distribution of BG values in the ranges indicated at various times of day. This could be useful to point out problems (hypoglycemia and/or hyperglycemia) at different times of day.

The graph below illustrates the percentage of time spent in three BG ranges on each day of the month. The numeric percentage is shown on top of the green bars for the % of time BG was between 61 and 110 mg/dl. My goal is for this to be > 70% of the time.

The graph below  simply shows the change in BG that occurs after weightlifting during the month. I think the variability in the BG response to exercise from day to day is quite remarkable. I think that the increase is related to stress hormones secreted during intense exercise. However, the degree of elevation is largely related to the basal (Lantus) insulin dose on any given day. There are some days where the BG actually dropped. Thus, the change in BG is a function of both the exercise activity and the current basal insulin dose.

In August, my goals include a further reduction in the frequency of hypoglycemia (my goal is none) and an increase in strength.  I will continue olympic weightlifting every day with 2 exercises per day. I will also continue metformin 2000 mg daily (1000 mg every twelve hours).

My Thoughts About Management of Type 1 Diabetes With A Ketogenic Diet

My goal of glycemic management in T1DM with a ketogenic diet is to keep BG as close to normal i.e. 96 ± 12 mg/dl (mean ± SD) as is safely possible (i.e. avoiding hypoglycemia) to avoid diabetic complications, a reduction in lifespan, and unpleasant symptoms of as well as injury and death from hypoglycemia. For me, a well-formulated whole-food nutrient-dense ketogenic diet, daily exercise, frequent BG measurements, and lower insulin-analog doses (Humalog/Lantus) have improved my glycemic control, hypoglycemic reactions, and quality of life. My basic diet philosophy is to avoid processed foods especially those containing refined carbohydrates, sugar, and vegetable (seed) oils while enjoying whole foods (with just one ingredient) as close to their original state as possible. I think just knowing the guidelines in this paragraph would be a good start for those wanting to improve their diet. To treat diabetes, the additional step is to eliminate all foods with significant amounts of carbohydrate to keep the net carbohydrate total < 50 grams/day. Some may do better with < 30 grams/day, while others who exercise a lot may do well with < 100 grams/day. Each person needs to determine their own level of carbohydrate tolerance to optimize their BG.

My Whole-Food Low Carb Ketogenic Diet

What I Cook & Eat

  • Beef, grass-fed, including meat (85% lean), heart, liver, and kidney (liverwurst)
  • Fish, mainly wild Alaskan salmon
  • Lamb, Chicken & Turkey occasionally
  • Chicken Eggs (one per day)
  • Non-starchy vegetables (about 5% carbohydrate content by weight) including Cabbage (Red, Green, Napa), Kale, Collard Greens, Home-made Sauerkraut from Red Cabbage, Bok-Choy, Broccoli, Cauliflower, and some others.
  • Fruit – Avocado, Olives, lemon juice on fish
  • Nuts & Seeds – Pepitas, Macadamia, Brazil, Pecan, Walnut, Pistachio, Cashew.
  • Note: I developed an intolerance to milk prior to my diagnosis of T1D. I did try heavy whipping cream after starting my KLCHF diet, but am also intolerant of it. I do tolerate butter, but wanted to decrease my fat intake to further improve my body composition, so eliminated all dairy including cheese and yogurt.

What I Drink

Water (filtered by reverse osmosis), Unsweetened Tea & Coffee

What I Don’t Eat

  • Grains – Wheat, Corn, Rice, Oats (there are many more) or anything made from them, which is too numerous to list here. Gluten is a protein present in a number of grains (all varieties of wheat including spelt, kamut, and triticale as well as barley and rye.) which can cause a number of medical problems for a significant portion of the population with gluten sensitivity or celiac disease. In my case, I avoid them due to their carbohydrate content.
  • Starchy and most root vegetables – potatoes, sweet potatoes, yams
  • Legumes – peas, beans, lentils, peanuts, soybeans
  • High sugar fruits – includes most fruits except berries, see above.
  • Sugar and the fifty other names used to disguise sugar.
  • Vegetable Oils - Canola, Corn, Soybean, Peanut, Sunflower, Safflower, Cottonseed, Grape seed, Margarine & Butter substitutes, Shortening.
  • All Processed Foods.
  • I avoid restaurants except when traveling, and then order fish or steak with plain steamed non-starchy vegetables (no gravy or sauces that typically contain sugar, cornstarch, or flour) or salad.
  • Refined, but healthy, fats – Although there is nothing bad about including butter, coconut & olive oil in a ketogenic diet, I have eliminated refined fats from my diet to further improve my body composition.

What I Don’t Drink

  • Colas (both sweetened and artificially sweetened).
  • Fruit Juice except small amounts of lemon juice occasionally.
  • Alcohol (can cause hyperglycemia or hypoglycemia in persons with diabetes).
  • No artificial sweeteners: I don’t enjoy them, but for others they may act in the brain to fuel carbohydrate cravings and would be best avoided.


  1. Efficacy and safety of metformin for patients with type 1 diabetes mellitus: a meta-analysis – here
  2. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults – here
  3. Continuous Glucose Profiles in Healthy Subjects under Everyday Life Conditions and after Different Meals – here
  4. Variation of Interstitial Glucose Measurements Assessed by Continuous Glucose Monitors in Healthy, Nondiabetic Individuals – here
  5. Severe Hypoglycemia–Induced Lethal Cardiac Arrhythmias Are Mediated by Sympathoadrenal Activation – here

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