An Insulin Resistance Lesson for People Who Zoned Out During Biology Class
Get ready for a quick biology lesson from someone that is not at all qualified to provide this.
Your body loves glucose! It’s the main energy source for all of your cells. When you shove your mouth hole full of food, it gets digested. Digestion is merely the way for the body to break all that stuff down into the most usable parts. For the most part, this comes in the form of amino acids (from protein), glucose (from carbs), and fatty acids (from fat).
There is definitely more nuance to all of this, but we’ll keep this simple for now.
When you eat carbs, insulin steps in to help out. It also shows up when you eat protein — just not nearly as much. And for fats? Hardly at all.
The main takeaway: carbs cause the biggest insulin spike. This is simply because your body breaks carbs down into glucose, which enters your bloodstream and needs to be managed. Insulin’s job is to get that glucose out of your blood and into your cells, and if there’s too much, store it as fat. It acts as the key that unlocks the cells so that glucose can get in there.
The beautiful thing about the body is that this is completely normal! You eat, you digest, insulin gets fuel to your cells, the liver stores leftover glucose as glycogen (just a more complex version of glucose) and insulin levels subside. Rinse and repeat.
Well, what happens when there’s too much glucose?
Your body responds by pumping out more insulin to handle the excess. Over time, your cells start to resist that constant insulin signal (because they’re already full of fuel), so your body produces even more insulin to force the glucose in.
And thus, a beautiful, bouncing baby of insulin resistance is born!
Stealing an analogy from Dr. Jason Fung: picture a subway car (that’s your cell). Normally, people (glucose) can enter without a problem when the doors open (insulin). But when that car is full, the doors open and people are spilling out, yet there’s still a massive crowd at the station waiting to get in. That’s when your body sends in subway pushers (more insulin) to cram more passengers into an already packed train.
When insulin is constantly elevated like this, your body starts scrambling to find somewhere to put all that glucose, and the overflow ends up being stored as fat. At that point, your metabolism gets knocked out of balance. So even when you’re eating less, your body isn’t burning fuel effectively because it is literally stuck in storage mode.
Ergo — and yes, I just like saying “ergo” — a calorie deficit alone doesn’t cut it when insulin resistance is wrecking the system.
Lesson over. Class dismissed. No refunds.
