As I previously described in my blog, “The Dreaded Oral Glucose Tolerance Test,” I had the pleasure of taking three glucose tolerance tests (OGTT) for the study I recently participated in. My body had no idea what to do with 75g of glucose during the first OGTT, but seemed to learn how to handle it better for the second OGTT. However, I failed both tests, as passing the OGTT requires a two-hour glucose measurement of less than 140mg/dL. My glucose concentrations were 185mg/dL and 176mg/dL, respectively, for the two tests. I wasn’t even close to the magic number of 140mg/dL, but I had a plan for passing!
The internet consensus was that people on a low-carb diet should eat at least 150g of carbohydrates for at least three days prior to the OGTT in order to prepare for it. Struggling with achieving stable glucose after OGTT #2 and a desire to enjoy my Memorial Day weekend led to a change in my continuous glucose monitoring experiments. I actually welcomed the change of pace because the controlled glucose experiments during the first ten days were pretty predictable.
More about that later, but basically, if I had stable blood glucose and ate something with appreciable sugar, my blood glucose levels would rise and quickly fall back to baseline. The more glucose, the bigger the effect, but I always either fasted or avoided sugar to return to equilibrium. When I ate low carb, my blood sugar was relatively unchanged. This gave me the opportunity to see how specific foods and beverages affected my blood sugar. It was almost too easy… and showed me how well my body responds to a low carbohydrate diet.
I started thinking… What if I threw my healthy eating habits completely out of the window and enjoyed the standard American diet (SAD) for the second 10-day period? What would that do to my blood sugar, and better yet, how would that affect my final OGTT at the end of those ten days?
It probably didn’t help that I had just watched a documentary called “That Sugar Film” on Amazon, where a guy from Australia ate 40 teaspoons of sugar per day, while choosing seemingly “healthy” foods. He did eat sugar directly one of those days to illustrate the sheer volume of his consumption, but otherwise, the sugar he chose was all hidden from convenience food.
I’ll talk more later about how the 10-day SAD made me feel after over five months of healthier eating. I’ll also share what it did in the short-term to my blood sugar, as well as how it affected my HgA1C (which is a 2-3 month average of blood sugar). But, first, let me share what happened on my final OGTT.
The first observation I had is that I didn’t feel as terrible during this test as I had for the previous two OGTTs. I didn’t feel great, but my symptoms were much more tolerable. I guess my body was over the whole sugar thing! Here is my curve for the final test:
My fasting blood glucose started higher at 96 mg/dL (lab sample was 80mg/dL), as did my fasting insulin, which was now 4.4mIU/dL. I guess ten days and two OGTTs had an impact on both my fasting blood sugar and my insulin levels. My glucose and insulin both rose very quickly, and my maximum glucose concentration slightly broke the record once again! The new record stands at 242mg/dL and it only took 45 minutes to get there! However, my insulin only rose to 76.1mg/dL, which was significantly less than OGTT #2.
I found that interesting that it took less insulin to accommodate the 75g of glucose, although my blood sugar rose a little higher. My glucose and insulin concentrations started to come down from their maximum, but for some reason, they hung up on the way down. At two-hours, the decline started again, and it was fast and furious! My two-hour lab glucose concentration was 135mg/dL, which is passing! Unfortunately, that’s where the fun ended.
My glucose continued to plummet and by the second to last data point, I had a blood glucose of 50mg/dL and felt horrible due to hot flashes and shakiness. This was the worst and earliest hypoglycemia symptoms that I experienced. The last data point rose slightly to 55mg/dL for the last measurement of the study, but I couldn’t even leave the study location without eating sugar and waiting for my glucose to rise. I felt horrible again after getting on the glucose roller coaster and the rest of the day was pretty rough.
Bottom line is that although my glucose went up high and got stuck on the way down, at the end of the day, I had a passing score. Should I be happy that ten days of eating the SAD allowed me to “pass” the OGTT? Probably not… but, failing it doesn’t really help me either, and clearly a low carb diet set me up for failing. I’m sure that longer time on the SAD would allow my blood sugar and insulin response to equilibrate, but I’m not willing to do that test for several good reasons.
First, I hate the way my body feels when it’s running on sugar:
I have more inflammation and thus more pain, especially when it comes to pressure from my aerial yoga hammock.
I don’t sleep as well at night and am more tired during the day.
I am more irritable.
I look like I’m well into my second trimester, but I’m not pregnant!
Second, I don’t ever want to do another OGTT, as they make me feel absolutely horrible.
Finally, I don’t see the purpose of the OGTT. Supposedly, it’s to determine if you have diabetes or gestational diabetes, but is the test valid? Unless you think consuming 75g of sugar in a 10-minute time period is a good behavior to indulge in, the OGTT isn’t exactly indicative of normal consumption. Why does it matter how my body responds to a large sugar load? It’s not healthy to consume that much sugar!
In fact, the 2015-2020 Dietary Guidelines for Americans recommends that calories from added sugars be limited to 10% of total calories. Assuming a 2000 calorie/day diet, that would be no more than 200 calories or 50g of added sugar per day.
The American Heart Association takes it a step further and recommends women only have a maximum 25g of added sugar per day. That’s a lot less than 75g in 10-minutes!!
I feel like it’s important to understand how your body responds to sugar, both in terms of how much it goes up, and how quickly it comes back down, but the load of sugar should be proportional to the diet that is consumed. I also believe insulin levels should be factored in. If you eat low carb and have a low fasting insulin and your body isn’t used to processing loads of sugar, of course it’s going to freak out when you drink 75g of glucose in a short time frame!
What fascinates me is that if you are diagnosed with diabetes or gestational diabetes, the first recommendation would be to eat a low sugar diet. However, eating a low sugar/carbohydrate diet may be what caused you to fail the OGTT in the first place! At least that’s what happened to me!