I bought a continuous blood glucose sensor and stuck it up my arm for two weeks
I have OCD: obsessive compulsive disorder. When it comes to health, I have used my OCD to good effect, to quit one bad habit after another. I was obese, so I took up running. Then, I serially quit drinking, smoking, coffee, cakes (which I love), processed foods, fried stuff.
I had imagined food science was relatively stable, maybe not as anchored as Newtonian physics, but steady enough to set some dietary rules. I soon discovered that food science is totally dynamic, so ever-evolving as to be almost unreliable.
In effect, there’s a villain in every study. But worse, this villain keeps changing. For instance, fats, especially saturated fats, were considered responsible for everything from heart disease to obesity. So I quit ghee and butter and also nuts, which I loved. Later studies suggested that fats may, ironically, even be good for the heart. So I picked up nuts again thank god. Then the focus shifted to carbohydrates. I cut down rice and switched from processed to whole wheat flours.
Now, research suggests we have got it all wrong. It’s sugar that’s to blame for all our ills. Our bodies aren’t made to handle sugar because it’s a recent food innovation. Also, like drugs, we get addicted to sugar. The chemical that sugar releases in our brain is the same as that released by cocaine. Importantly, a sustained level of high blood sugar can cause organ damage, and may lead to strokes and heart attacks. This sounded scary.
Now, I am no expert, just a normal person trying to stay healthy. When I see these studies, I take them seriously. I decided to cut my sugar intake. It began with no sugar in tea, and soon I’d cultivated a taste for it. Juice packs were returned and ice-cream consumption reduced (I can’t ever give it up entirely).
They said there’s a high likelihood that all packaged foods — biscuits, chips, yoghurt — have some added sugar. Even breakfast cereals. So, I replaced cereal with oats. Then someone said even oats have added sugar. This broke me.
Imagine yourself in my position for a moment. I am a vegetarian in Sweden where my options are limited at best. I like a heavy breakfast that can carry me through most of the day. And I could not have bread or cereals or oats.
So I decided to measure how food really impacts me personally. While there are general theories on foods and their glycaemic indices (a figure that indicates how much a carbohydrate increases glucose levels in the blood), it’s also a known fact that not everyone reacts to the same foods in the same ways. Also, the body’s ability to process sugar changes with age. Given all these unknowns, I decided to find out how my body responds to sugar before mindlessly removing yet another item from my diet.
DIY sugar hack
So I designed a DIY experiment. I bought a continuous blood glucose sensor and stuck it up my arm for two weeks. My wife thought I had gone a step too far this time, but she just rolled her eyes. For two weeks, I measured every food I ate, the resulting glucose level in my body, and how long it took for the level to return to normal. On the way, I isolated each food (for instance, a banana or a spoon of rice) and measured its impact independently. Here’s what I found out.
(I would like to reiterate that I am not a doctor, I am simply curious about this stuff. So please don’t take inspiration from my findings to change your food habits.)
Invariably, I start my day with a glass of lukewarm water with lemon and a teaspoon of honey. I was surprised that the glucose level shot up immediately, but I shouldn’t have been. Honey is pure sugar, and the peak was expected. The peak subsided within 45 minutes, the time I take to shower and meditate. Interestingly, this peak was the highest I would see through the day on most days. Essentially, I was starting my day on a sugar rush. But honey also has fantastic anti-inflammation properties, so I decided to keep it in.
I wanted to test cereal against oats for breakfast. Cereal caused blood glucose to rise and fall in a short time, whereas oats led to a more stunted peak that tapered out gradually over the next few hours. So I decided to stick to oats, but not the pre-packed oatmeal that tends to have added sugar. Oats kept my energy sustained for a longer duration.
In general, I noticed that fruits (banana, apple, sometimes pear) did not lead to noticeable highs; protein shakes did not either (I drink a low-sugar version, but not all protein shakes are low in sugar), whole milk or lactose-free milk didn’t show any difference, and cottage cheese, my favourite snack, did not even cause a blip on the blood glucose trend line. So far, so good!
What’s for dinner?
Then I began to study lunch and dinner. I mostly eat dal and vegetables with rice. With this food, the peaks were more noticeable, expectedly, for these carbohydrates process into sugar during digestion. I was surprised though at how quickly the glucose increases, indicating how fast the body processes food. But it also returned to normal within two hours, if not earlier.
In one experiment, I added ghee to the rice (white rice has a high glycaemic index) and discovered that the glucose peak truncated considerably. The fat (ghee) added to rice or roti lowered the glycaemic index of the carbohydrate. So I put ghee back in.
Another interesting thing I noticed was my body’s reaction to food on days when I rested well against more stressful days. On days when I hadn’t slept much and was rushing from one meeting to another, my glucose levels looked like irregularly shaped peaks and valleys. On the more rested days, like weekends, my glucose profile was more or less steady. Can stress cause glucose levels to fluctuate that much, I wondered? Maybe we need a study to explore a possible correlation.
Steady exercise mostly caused the glucose to plummet. Whether I lifted weights or ran, it tended to come down.
After two weeks of experimentation, I took off the sensor. In those two weeks, I had learnt that while it’s okay to be aware of what foods spike blood glucose, the body also has an inherent mechanism to normalise the glucose through insulin.
I don’t have to avoid all sugar (for instance, honey), but it makes sense to not overdo processed and sugary foods. I could feel the impact of glucose spikes and crashes on my body. With consistent levels, I was more energetic and felt less hungry between meals. I also realised that certain Indian food habits have good sense behind them.
On the whole, the body hack gave me a good sense of how my body operates, what I should eat more, and what I should avoid. Finally, I had managed to put my OCD to some good use.