Contents

• Why do it?
• The objective
• The experiment
• Key learnings
• 1. Assessing your metabolic health - variability and avg level
• 2. Nutritional biochemistry
• 3. Foods I used to think are healthy/New perspective on certain foods
• 4. Effect of Exercise
• 5. Effect of fiber
• 6. Hawthorne effect
• 7. Poor sleep
• 8. Glucose crash and hunger
• 9. Metabolism is just one part of a healthy diet. You can't eat bacon all day
• Other details
• Footnotes

Why do it?

Some people gain weight at the sight of dessert whereas others have a free pass when it comes to gaining weight. Why? Well, one explanation is Metabolic health and the reason I decided to wear a Constant Glucose Monitoring device for 30 days is to assess my own metabolic health.

In the long run, poor metabolic health has even more serious consequences than weight gain. Poor metabolic health leads to insulin resistance which directly leads to Type 2 diabetes and dramatically increases the chances of Heart Disease, Cancer and Neurodegenerative diseases[^1]. My point is not to scare you but to highlight that with today's technology you can assess your metabolic health and act on it before its too late. [^2]

The objective

The goal with this experiment was to understand 3 main things

1. How my Metabolic health is currently
2. How different foods affect my metabolic health (This will be unique to me)
3. How to improve my metabolic health

The experiment

Wear a Constant glucose monitor for 30 days and observe which foods and behaviours affect my metabolic health and how.

The Sensor gives 3 primary data points

1. Your average blood glucose throughout the day - The lower the better between 70-110 mg/dL
2. Your glucose variability throughout the day - Below 12% is ideal
3. Sugar level Vs Time graph shortly after an event (Eating, exercising, High stress event etc)

Interestingly, my dad and I did the test together to really see the difference between how different foods affect people differently. We got our CGM sensors from Ultrahuman[^3]. Even though the sensors are the exact same sensors from Abbot that diabetic patients use, the Ultrahuman app really makes a big difference for regular people looking to do this experiment.

Key learnings

1. Assessing your metabolic health - variability and avg level

The most important metric you get is your avg glucose throughout the day. You want to be in the lower range of 70-100 mg/dL . Above 100 is worrying, over 110 is pre diabetic and over 120 is considered diabetic [^4]. In other words, this avg glucose over 30 days is the same thing as the Hba1c in your regular blood report (the blood report is more accurate, but this gives you insights on a daily basis).

The second thing to look at will be variability. Each time your glucose levels rise, insulin is released to convert unused energy into fat. With years of abuse to your metabolic health, your body starts becoming resistant to this insulin. So the less your glucose levels vary during the day, the less insulin is produced. Before 12% is good, but lower the better.

2. Nutritional biochemistry

Different foods affect different people differently. On a particular day, me and my father had the exact same lunch with the exact same quantity (Rice + Rajma) and the response we both got from it was dramatically different. First image shows the response my dad saw. The sugar levels spiked by as much as 70 mg/dL and stayed well out of zone for a very long time.

After experimenting with different combinations of food, what my dad realised is that rice does not suit his metabolism very much. He has since reduced rice in his diet and felt a significant difference in his body weight and energy levels after the meals.

On the other hand, my glucose levels never go out of zone and the food gives me gradual release of energy for hours after as well.

3. Foods I used to think are healthy/New perspective on certain foods

After experimenting with 93 different food items, I've got a very new perspective on certain food items. Some of them are below

Subway

I used to think that a subway sandwhich is one of the healthier choices in fast food. It was my go to option for eating healthy fast food. Here's my graph after a Footlong chicken sandwich

Very evidently, this meal gave me the worst response of all the foods I tried. The only possible culprit for this could be the refined carbs in the bread (or the sauces but i get very little of them). What's even worse is that if you've exercised during the day, that helps reduce the impact on your blood glucose levels (more on this below). But with subway, even after doing a 60Km Bike ride or running 10km+ I get a similar response.

Keloggs cereal

I usually keep two different cereals at home. One would be a guilty pleasure (Think fruit loops or Chocos) and the other a healthier choice (Or so I thought) with higher fibre and protein content (Keloggs Special K or Vector). You can probably guess it already. The exact same response from both cereals. Yes, the cereal marketed to be healthier gave me the exact same response as other sugary cereals. I suppose any amount and any form of refined carbs don't suit my metabolic health

Pasta

Even though it is supposed to be carb heavy, a homemade pasta with whole grain (as opposed to refined grain) gave me a surprisingly good response. No spike and a steady release of energy after.

4. Effect of Exercise

Besides changing the food selection, exercise has the biggest impact on your metabolic health. Some professional would even argue that it is more important than the food itself. On a normal day, having my favourite Peanut butter and banana homemade milkshake sends my glucose outside target zone.

But if I exercise before it (1hr Zone 3 Bike ride or similar), then my glucose barely budges. And this includes days when i exercise early in the morning and have my shake in the afternoon. Unsurprisingly, if I have exercised during the day my avg glucose stays considerably lower the entire day. What I found most shocking is that even a small 10 min walk after your meal reduces the impact significantly.

Furthermore, the way insulin spikes lead to insulin resistance, exercise helps improve your sensitivity to insulin. As a result, it is one of the best tools to undo any damage already done to your body in terms of insulin resistance.

5. Effect of fiber

After exercise, the best way to reduce the effects of carbs on your metabolic health is through fiber. Fiber helps slow down the absorption of the sugar in your food resulting in a gradual glucose response. For example, look at the glucose response I had after eating a Banana.

Very nice and steady with only a minute increase in sugar levels. What's interesting is that a typical Banana has 23g of Carbs. The healthy cereal I covered above has about 25g of Carbs. Even though the difference in carbs is small the difference in body's response to it is huge. And as you've guessed it, the reason is the fiber content in banana which slows down the absorption of the sugar.

An interesting thing I noticed is that all sweet things that exist naturally exist with fiber and that's how they are supposed to be consumed. Yes, that also includes cane sugar which is used to make processed sugar. The cane sugar exists in cane with loads of fiber which we discard during processing of foods.

For the same reason, eating salad before a meal helps line your stomach with fiber which then slows down the absorption and the glucose response is a lot more steady and gradual.

6. Hawthorne effect

Hawthorne effect is the phenomenon where people change their behavior when they are aware that they are being observed. In the past, even though I've known that a midnight dessert is no good for my metabolism I still enjoyed the guilty pleasure. With the CGM on, because I knew something was keeping track of my bad habits, I was a lot more mindful and less likely to indulge. Interestingly, even after the sensor is off, the effect is still there in the back of my mind always.

7. Poor sleep

Surprisingly, poor sleep has a very strong correlation to avg glucose throughout the day. I noticed that the days I did not sleep well (because of red eye flights) my avg glucose was higher the next day even if I didn't have many carbs. For example, My avg glucose normally was around 75-80 during the 30 days. On days when my sleep was not enough (less than 6 hrs) my avg glucose for the entire day was 90+.

This explains to me why so many diseases whether they be neurodegenerative, cancer or cardiovascular are now being related to poor sleep. Poor sleep leads to poorer metabolic health which in turn increases the chances of ailments.

8. Glucose crash and hunger

Another downside of Sharp glucose spikes after a meal is that it also comes crashing down after. What I have also noticed is that each time I have a sharp crash, I feel hungry again even if I just ate an hour ago. In the past, after a carb heavy meal I would often crave something sweet an hour after the meal and would consume something like a chocolate or fruit even though my body does not need it. This results in unnecessary consumption of calories.

9. Metabolism is just one part of a healthy diet. You can't eat bacon all day

A very important detail to keep in mind throughout the experiment is that your body's glucose response to food is only one aspect of what makes a healthy diet. You could eat bacon all day long and your glucose scores will likely be good. But that does not mean eating only bacon is healthy. The whole point of this experiment is to learn healthy habits around your metabolism. Other aspects of a diet such as protein, essential fats, minerals and vitamins are just as important.

Other details

Footnotes

[^1]: Based on Outlive: The Science & Art of Longevity — New Book by Peter Attia

[^2]: It should be noted that there are no clinical studies showing the benefits of using a CGM in the non diabetic population yet. However, as highlighted in the book Outlive by Peter Attia, there are strong logical reasons supporting this experiment and nothing against it except for the cost of the sensor

[^3]: Ultrahuman | Pricing

[^4]: I’m far from a medical professional so these numbers are purely indicative and might be incorrect. I got these numbers from Outlive: The Science & Art of Longevity — New Book by Peter Attia