“But what about the insulin spike?” A lot of clients will ask me that after I’ve finished giving a lecture about how the only 2 things that matter for fat loss are calories and protein. And nothing else. Inevitably comes the question “what about carbs/sugar?” To which I answer “see my previous answer.” Carbs aren’t a problem. Excess carbs are a problem. Sugar isn’t a problem. Excess sugar is a problem.
Original source: here.
Eventually, we get to a point where they say “what about the blood sugar/insulin spike?”, to which I stump them, but repeating the question back to them – “what about the blood sugar/insulin spike?”
That’s when you see the record in their brain skip a beat. They don’t know what a blood sugar/insulin spike is, or why (they think) it’s bad. They just heard some guy, like either Huberman, Peter Attia, or a random guy with the username BigGunzBob on reddit say it’s bad.
In this article, you’ll learn about:
- The relationship between blood sugar and insulin
- What happens to blood sugar levels when you eat carbs/sugar
- What happens to insulin levels when you eat carbs/sugar
- How the blood sugar/insulin spike affects body fat levels
The Relationship Between Blood Sugar and Insulin
A lot of people use the terms “blood sugar spike” and “insulin spike” interchangeably. Why? Because they don’t know the difference. Let’s make sure you’re not one of those ignoramuses.
I don’t think I need to explain the term “blood sugar”. But insulin bears explaining. Insulin is a hormone. It has several functions, but as it pertains to blood sugar, it does one thing: lowers it. Simple enough?
What Happens to Blood Sugar Levels When You Eat Carbs/Sugar
Here’s what happens when a non-diabetic eats a carb-based meal:
- Blood sugar starts rising within 10-15 minutes of the beginning of the meal.
- It continues rising for about 60 minutes, when it peaks.
- It starts falling after that.
- Two hours after a meal, it should return to pre-meal levels.
This is regardless of the size or composition of the meal. Even if someone had a big bowl of pasta, a non-diabetic’s blood sugar will follow this pattern. That’s a healthy, normal, desirable pattern. If blood sugar didn’t rise in response to a carb-based meal, that would be concerning, because it would indicate a problem breaking down carbs, and releasing them into the bloodstream (typically a small intestine or liver problem).
This is different for a type 2 diabetic. Here’s how that would look:
- Blood sugar starts rising within 10-15 minutes of the beginning of the meal.
- It continues rising for about 60-120 minutes, when it peaks.
- It starts falling after that.
- It takes longer than 2 hours to get back to pre-meal levels.
Not only does a diabetic have a delay in the peak of the blood sugar, but there’s also a delay in the magnitude of blood sugar rise.
- The highest that a non-diabetic’s blood sugar will go after a meal is 7.2 mmol/l (130 mg/dL).
- The highest that a pre-diabetic’s blood sugar will go after a meal is 11.0 mmol/l (198 mg/dL).
- A diabetic has no upper limit how high their blood sugar will go after a meal. There’s just a lower limit: 11.1 mmol/l (200 mg/dL).
And there are also differences between the fasting levels of diabetics, pre-diabetics and non-diabetics.
- A diabetic’s fasting blood sugar is by definition 7.0 mmol/l (126 mg/dL) or higher.
- A pre-diabetic’s fasting blood sugar level is between 5.6-6.9 mmol/l (100-124 mg/dL).
- A non-diabetic’s fasting blood sugar level is 4.0-5.5 mmol/l (72-99 mg/dL).
If we do some basic math, we see the potential gap between the lowest and highest blood sugar levels.
- A non-diabetic’s lowest and highest numbers are 4.0-7.2 mmol/l (72-130 mg/dL). So the range is 2 mmol/l (58 mg/dL).
- A prediabetic’s lowest and highest numbers are 5.5 and 11.0 mmol/l (99-198 mg/dL). So the range is 5 mmol/l (99 mg/dL).
- An early-stage type 2 diabetic’s lowest number is 7.0 mmol/l (126 mg/dL), and no limit on the highest. Typically, our diabetic clients might go as high as 14-18 mmol/l (252-324 mg/dL).
Now you know why I don’t like it when I hear non-diabetics use the word “spike” to describe blood sugar increases.
For non-diabetics, there’s almost never a blood sugar spike (except in extremely rare cases where they have other problems with blood sugar). Only a blood sugar increase – a gentle increase, not a spike.
What Happens to Insulin Levels When You Eat Carbs
Now we know what happens to blood sugar levels in diabetics, prediabetics, and non-diabetics. But what happens to insulin (remember, insulin brings down blood sugar)?
In a non-diabetic, here’s how insulin works: When you eat carbs, blood sugar rises. The body detects it, and the pancreas releases a sudden but small burst of insulin. This is not proportional to the amount of carbs eaten so far. That’s called a “first phase insulin response.” As a non-diabetic keeps eating their meal, there’s a second phase insulin response, where the amount of insulin released is proportional to the amount of carbs consumed.
In a prediabetic and a diabetic, the first phase insulin response is either diminished or completely absent. That’s why their blood sugar rises higher than that of a non-diabetic. So the second phase insulin response has to do the work of both itself as well as the first phase insulin response.
Prediabetics and diabetics do indeed have an insulin spike.
To put some numbers to this:
- A non-diabetic’s peak insulin after a meal would be 347-486 pmol/l (or 50-70 µIU/mL).
- A prediabetic’s peak insulin after a meal would be 486-833 pmol/l (or 70-120 µIU/mL).
- A type 2 diabetic whose pancreas is still working would have a peak insulin spike over 833 pmol/l (120 µIU/mL).
Do you see now how non-diabetics never even need to think, worry or consider blood sugar and insulin spikes? Yes, diabetics and pre-diabetics need to do something about it, but non-diabetics need to stop reading/listening about these things (I hope this is the last article you’ll read about it). Unless these nondiabetics are professionals working with prediabetics and diabetics.
How the Blood Sugar/Insulin Spike Affects Body Fat Levels
The whole reason that people are even concerned about the blood sugar/insulin spike is because they think it’ll make them gain body fat. While neither a blood sugar nor an insulin spike (in the true sense of the word “spike” – not the gentle rise that we see in non-diabetics) are healthy, they have no effect on body fat levels whatsoever.
If excess insulin was the cause of fat gain, then lowering insulin would be the solution, right? That theory was tested. In one study, a group of researchers from the journal of Diabetes, Obesity and Metabolism took overweight people, and put them on a low-calorie diet. They were divided into two groups: one group was just on a low-calorie diet, and the second group was on the same diet, but they were also given the insulin-lowering drug diazoxide. The results: no difference in either weight loss or fat loss at the end of 8 weeks between the two groups.
So much for that. I elaborate on this in much greater detail in my articles on low carb myths as well as the (un)surprising reason why we get fat.
If you’re a non-diabetic, and need help losing body fat or getting toned, we have our Fitness Over 50 program. If you need help with that, just respond to this email with the subject line “Fitness Over 50.”
If you are a prediabetic or type 2 diabetic, and you need help reversing that, just respond back to this email with the subject line “Diabetes Reversal Help.”
Reaching out does not obligate you to anything. It’ll just set up a quick, 10–15-minute chat so that I can understand your situation, and see whether our services are for you. There’s no pressure, sales pitch or obligation.
