Why Your Carb Ratio Stopped Working (And Why It’s Not Your Fault)
You count the carbs perfectly. You weigh the food. You punch the numbers into your pump or calculate the dose for your pen exactly as your doctor taught you. The math is perfect.
And then, 45 minutes later, you watch your Dexcom arrow shoot straight up. You hit 250 mg/dL. You stay there for two hours, frustrated and exhausted, before crashing back down.
You assume the problem is the math. You think, "My insulin-to-carb ratio must be wrong. I need more insulin."
Here is the trap: If you change your ratio, you will likely go low next time. The problem isn't the amount of insulin. It’s the timing.
The "Right Amount" at the "Wrong Time" is Still a High
Standard medical advice teaches us to "Bolus and Eat." But this advice ignores the laws of physics.
The Reality: Standard rapid-acting insulin takes 15–20 minutes to begin working and 60–90 minutes to peak.
The Problem: Modern processed food (even "healthy" carbs) hits your bloodstream in minutes.
If you bolus and eat immediately, the food wins the race. It spikes your blood sugar before the insulin even wakes up. By the time the insulin starts working, it’s too late—you are already chasing a high.
The Solution: The "Tug-of-War"
Imagine your blood sugar is a flag in the middle of a tug-of-war rope. On one side is Insulin (pulling down). On the other side are Carbs (pulling up).
If you let the Carbs start pulling 20 minutes before the Insulin shows up, the flag flies into the sky (a spike).
To win, you must give the insulin a "head start." This is called a Pre-Bolus. By dosing 15, 20, or even 30 minutes before you eat, you allow the insulin to start pulling down just as the food starts pulling up. The forces cancel each other out, and the flag (your blood sugar) stays in the middle.
⚠️ The Safety Check (Read Before You Bolus)
Pre-bolusing is a power tool, but you must respect the current data. Context is King.
Never Pre-Bolus a Low: If your blood sugar is low (e.g., under 70 mg/dL) or your arrow is trending down, do not wait. Eat immediately. The "Tug-of-War" is already lost; you need the carbs to pull up instantly.
The "Pizza Effect": High-fat/high-protein meals digest much slower than standard carbs. If you pre-bolus a heavy meal (like pizza or steak) by 20 minutes, you may crash before the food digests. These meals often require an extended bolus or different timing.
Know Your Insulin: If you use ultra-rapid insulin (like Fiasp or Lyumjev), your wait times will be much shorter.
Stop Chasing the Ghost
You don’t need to change your ratio yet. You need to change your timing. You need to understand that "Timing and Amount" are equal partners. Even the perfect amount of insulin will fail if it arrives late to the party.
Ready to stop the spikes?
You don’t have to live on a rollercoaster. We break down exactly how to time your insulin safely, how to handle high-fat foods, and how to test your Pre-Bolus timing in the Diabetes Pro Tip Series.
Start Here:
🎧 Episode 1003: Pre-Bolus (The strategy that changes everything) - Apple Device, Spotify
🎧 Episode 1002: All About Insulin (Understanding how your tool actually works) - Apple Device, Spotify
🎧 Episode 1428: Small Sips Tug of War (The visual that makes it click) - Apple Device, Spotify
Stop blaming yourself for "bad numbers." It’s just data. And now you have the data to fix it.
