The Study That Proves Pre-Bolusing Works | 15 Minutes, 50 Points | T1D
Today Neil stops saying "trust me" and starts saying "here's the study." A trial published in Diabetes Care found that dosing rapid insulin 15 minutes before a meal dropped the blood sugar peak to about 167, versus about 221 when dosing at...
The episode, word for word
What if I told you 15 minutes could be worth 50 points?
Not dollars. Blood sugar points. The gap between landing at 180 after dinner and landing at 230. The gap between reaching for a correction and just leaning back in your chair like a man who has his life together. Same food. Same insulin. Fifteen minutes.
Today I stop saying "trust me, I've done this 34 years" and start saying "here's the study." You earned the science. Let's go grab it.
I'm Neil Greathouse, this is Your Best T1D Year.
So. There's a study in a journal called Diabetes Care. Reputable. Boring in the best possible way. The kind of journal that has never once gone viral and is very okay with that. And they tested one simple thing. People took their rapid insulin 15 minutes before the meal, versus right at the meal.
Dose 15 minutes early, blood sugar peaked around 167. Dose right at the meal, same people, peaked around 221. That's about a 50-point difference. From timing. Nobody changed the dose. Nobody changed the food. They just moved the insulin a little earlier and the number quietly behaved itself.
Sit in that for a second, because of all the energy we pour into this disease. We agonize over the dose. Did I count those carbs right, is my ratio off, should I have rage-bolused that burrito the size of a rolled-up yoga mat. And this study just strolls in, leans on the doorframe, and goes, "Or... leave the dose exactly where it is, take it a little earlier, and drop your peak by 50 points." Cool. Great. Where was this energy in 1998.
And 50 points is not nothing. Fifty points is the difference between a 180 you've forgotten about by dessert and a 230 that follows you around all night like that one tab you can't find that's playing music somewhere. Fifty points is a Caitlin Clark first quarter. Thrilling in a basketball game. We do not need that kind of scoring from a sandwich.
Now, there's a second study I love, in a journal called Diabetes Technology and Therapeutics, and it hands us the twist that keeps us from getting weird about this. They tested dosing 20 minutes before, at the meal, and 20 minutes after. Twenty early won clean, at the one-hour AND the two-hour mark. But, plot twist, in that first study, dosing 30 minutes early did NOT beat 15. Fifteen was the sweet spot. Go too early and you start dropping before the food even arrives, which, hello, is the exact fear we're camping out on all next week.
So it's not "earlier forever." This is not a competitive sport. Nobody is handing out a gold medal for pre-bolusing 45 minutes ahead and then gnawing on a dinner roll to survive while you wait. There's a window, and for most of us on regular rapid insulin, it's somewhere around 15 to 20 minutes before dinner. That's also exactly where the big 2018 review landed when it stacked all these studies together.
And your sweet spot is yours. Mine might be 15. Yours might be 10. Your buddy's might be 20. That's not a bug, that's the whole system. The back half of this challenge is just you, a scientist in your own kitchen, hunting your number.
So just to recap. The fix for years of post-dinner mountains was to push one button slightly earlier. We have had this technology the whole time. Bold strategy, us.
The Odyssey hit theaters today, Matt Damon burning the entire summer trying to get home. You've got a shorter trip. Fifteen minutes before dinner. Zero sea monsters. Worst case, a slightly impatient toddler.
Your challenge, still your dinner lab. This week, get honest about your natural timing. When you sit down, are you dosing early, late, or mid-chew? Find your starting line. Next week we look the fear dead in the eye, this time with data, and then we finally start.
And if you're just finding us, jump in. yourbestt1dyear.com, sign up for the newsletter, grab the freebies, follow along. You'd be joining about 1,500 people doing this together from all over the world.
T1D is relentless. But managing it does not have to be. Sometimes it's just 15 minutes, found in the exact spot it was hiding the whole time.
I'm Neil. Have a great weekend, and I'll see you Monday.
This is the script as read on the mic, lightly tidied for reading. Education, not medical advice. Talk to your care team before you change anything about your insulin.