O Level Biology Notes Reddit
Francoise Witsell
2. Second, several mamas in my Real Food for Gestational Diabetes Course have used CGMs to better understand and manage their blood sugar levels. In one case, CGM readings revealed really interesting blood sugar patterns overnight and at fasting (first thing in the morning) that ultimately prevented misdosing medications that could have caused hypoglycemia overnight.
3. Third, I had comprehensive blood work done a few months ago, which included a variety of metabolic markers. My HOMA-IR, a marker of insulin resistance, was almost too good (indicating favorable insulin sensitivity) and my fasting insulin and blood sugar were relatively low. While my results were overall very good, I was curious about what was going on with my blood sugar on a day-to-day basis.
I chose the Freestyle Libre for ease, functionality, and cost. Most CGMs require calibration with fingersticks using a glucometer (often with twice daily). Freestyle Libre is factory calibrated, so no need to poke your fingers all the time. This is both a benefit and a limitation of the system. It also tends to be less expensive than other CGMs.
UPDATE: One other option for obtaining a CGM is to use a company like Levels, which will connect you with a provider to see if you qualify for a CGM. This was not an option at the original publishing of this article, hence the update here. Use this link to get to the top of the 100k+ waiting list.
This will vary by your location, your pharmacy, and whether insurance covers it or not. For me, insurance did not cover it. The only pharmacy near me that carried the Freestyle Libre was Walmart, which apparently has great pricing on prescriptions.
*At the time of writing the 10-day sensor is the current norm in the U.S. They also manufacture a 14-day reader that was recently approved by the FDA (which, for reasons beyond me, is already the standard in other countries).
I swear it was just as easy as a fingerprick. It did not hurt at the moment, but it does make a tiny wound where the sensor is implanted under your skin. For me, that was a little bit sore, like a very very very dull ache (pain scale 1/10) the next day, akin to the feeling after getting blood drawn.
This shows how easy it is to take a real time blood sugar reading from the Freestyle Libre continuous glucose monitor. Press the button on the reader, bring it close to the sensor on your arm, and voila!
In some ways, my results were surprising and in other ways, exactly as I would expect. My goal was to test my regular diet and see how my blood sugar fared with my usual low-ish carb, real food, mindful eating approach. There were a few unusual meals, including Thanksgiving dinner and the morning I intentionally ate oatmeal (more on that later!); otherwise, I was just eating as I always do.
First off, is my blood sugar truly low? Maybe. Last time I had blood work drawn (meaning a venous blood sample), my fasting glucose was 68 mg/dl. This was after a 14 hour fast (not intentional; my appointment got pushed back that day).
This makes me think the Freestyle Libre readings were accurate. My fasting insulin levels were also on the low side, which is physiologically to be expected when fasting. The body is going to preferentially switch to burning fat/ketones and meanwhile both glucose and insulin will decrease during extended periods without food.
My readings were still within an acceptable range of variation, but I did dig up a few articles in the medical literature that suggest that Freestyle Libre readings can be a little off, either from a factory calibration error or other factors. Even so, observing the overall patterns in my blood sugar was invaluable.
Another interesting finding was my oatmeal test. Now, for the duration of the experiment, I ate my normal breakfast, which is typically some variation of 2 eggs cooked in butter or lard, vegetables (usually rotating between kale, broccoli, mushrooms, onions, etc.), and possibly some breakfast meat, like sausage or bacon. Alongside this, I have black tea (unsweetened) with heavy cream. [Read: I eat a low carb, high fat, moderate protein breakfast.]
All things considered, this was NOT a large bowl of oatmeal and it was essentially NOT sweet, despite adding a little honey. (I say this to point out that the average person adds A LOT of extra sweeteners to their oatmeal, either with sugar/honey or dried fruit. My version would be unpalatable to many people.)
At first, I thought my blood sugar was doing ok after the oatmeal, but I then watched with horror on my Freestyle Libre as the readings climbed. When you scan the sensor, the Freestyle Libre reader shows an arrow next to the numerical reading with an up, down, level, or slightly up/down error, indicating your real time blood sugar trends. This was the ONLY time during the entire 10 days that I saw the straight up arrow, indicating my blood sugar was rising FAST.
A subset of the study group were given standardized meals to measure the glycemic response. In the test of cornflakes and milk (which is nutritionally similar to my oatmeal breakfast), fully 80% of people without diabetes experienced blood sugar spikes beyond 140 mg/dl (prediabetic levels). Furthermore, 23% of this group saw blood sugar levels exceeding 200 mg/dl (diabetic levels) after cornflakes and milk.
The average amount of time spent above the normoglycemic range (blood sugar over 140 mg/dl) was 32 min per day in the normoglycemic group and 53 min in the prediabetic group. The peak blood sugar reading for non-diabetics averaged 119 mg/dl (compared to 128 mg/dl in the prediabetic group).
Specifically, prediabetic Biggest Loser applicants had 17.6% of blood sugar readings above 140 mg/dl while non-diabetic Biggest Loser applicants had 11.8%. Meanwhile, non-diabetic adults who are not morbidly obese only experienced 0.3-4.1% of readings above 140 mg/dl.
All things considered, I think what these studies highlight is that modern, high-carb diets are a mismatch for our physiology. The research has a name of it: evolutionary discordance hypothesis.
The key here is that if occasional blood sugar spikes are ancestrally normal, it was also ancestrally normal to have periods of time WITHOUT blood sugar spikes. That is something that is missing from modern life for most of us.
Furthermore, all my other lab markers of blood sugar and insulin regulation are good. Fasting insulin is low, HOMA-IR (a marker of insulin resistance) is good, leptin:adiponectin ratio is good (this is another surrogate marker of insulin resistance), A1c is good, all lipids are optimal, CRP is low, BMI is normal, etc.
I was able to tolerate potatoes, sweet potatoes, winter squash, beans, real sourdough bread, and fruit (eaten whole) without a spike my blood sugar so long as I ate them in reasonable portions (about half a cup at a time) and alongside fat and protein (thus lowering the glycemic load) and lots of non-starchy vegetables (fiber & phytochemicals). I learned that rice, oatmeal, and hidden sugar did not work well for my body.
Eating for better blood sugar balance has carryover benefits to the rest of your health. I think the key with CGM is to try to observe other symptoms and how they relate to your glycemic response to a meal.
That was a fascinating write up! You are by far the standout in this space regarding pregnancy nutrition and healthy diet. So scientifically sound, honest, reasonable and real. Thanks for this detailed article!
Yeah, as I share in the article, my Thanksgiving meal had the same (or not more) carbohydrates than the oatmeal and my glycemic response was significantly lower, likely because it was a mixed meal with fat/protein.
Thanks so much for this great article! I have a history of GDM and will still occasionally check my sugars, but have struggled trying to figure out what is a truly normal response to a higher carb load so your research is very interesting!
A real eye opener, thankyou for the great article.
One of the doctors I work with asked my advice for a low carb/ real food dietitian for pregnancy and resources for a friend and I gave her your name. I hope she read your work!
Great article Lily and hope one day soon the Libre will be available wo a prescription like glucometers are now. The glucometer and CGM are such powerful behavior modification tools as you demonstrate. I need to get one and wear it for the 10-14 days to learn more.
Also curious about your usual physical activity level. It would be interesting to see how a day of just moving more (life chores/tasks) affects BG versus an hour of high intensity exercise followed by a full day of desk work (my typical day).
Hi Lily,
Thanks for the great insights.
As you are already low carb, it is not surprising to see spikes in blood sugar with even little bit of carbs (rice and oats) in your experiment. During low carb eating, glucokinase is down regulated and physiologic insulin resistance kicks in which means glucose takes lot longer to get disposed of as compared to someone healthy who is not on low carb. This is at least true for most low carbers including myself. An OGTT taken in this state looks scary. It would be very interesting if you ate 150g carbs per day for 3 days at least and then monitored your blood sugar response to carbs.
The fetal origins of disease
Nutrition during pregnancy is important for more than just supporting the growth and development of the fetus, though. It also programs the metabolism of our children for the world they will be born into.
However, I will also add that for me, wheat and oats are a one way switch. My BG rises to as much as 20 (360 American) and does not go down until the grain is expelled. Rice spikes a bit less and goes down. Even straight sugar is not so potent, although I have never attempted to eat a similar amount. Using cream as a source of fat moderates the spikes and eliminates hunger on the downslope.
c80f0f1006