You're definitely making me reconsider it, thanks! Along with the person in another thread saying walks after meals help as well. With a fully remote work these risky "oops I injected but there's no food yet" situations should not happen as often, considering the time-to-fridge is like 10 seconds.

Knowing little about the subject. If Insulin is a 20 minute lag, and eating is a 20 minute lag. Shouldn't you just dose immediately before eating so they hit at the same time?

It's a very rough rule of thumb, take these numbers with a grain of salt. It could very well be that some food activates in 5 minutes etc. Different insulin types also have different curves.

Anyways there are studies about the "inject 15min before food" approach: eg. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2945151/

You forget one very important rule: it's all vibes :D No but seriously: insulin starts to act after 20mins. Its action is more like a flat parabola.

Glucose acts more in harsh peaks. So you want the glucose peak to hit when you are at the maximum of insulin action. Hence the 15mins delay.

This is all roughly speaking, YMMV.

It's hard at first. It is a habit to take, and you have to withstand a bit of social pressure first, when you're late with taking insulin and still want to wait. But I root for you, you can do it!!

one more tip I want to share: when you have a dramatic hypo or your blood sugar is dramatically high, double-check with the old school prick-test device. Your CGM might exaggerate. That stopped some nefarious cycles of being too high, then too low etc. for me.

Type 1 here. I also agree. With comment above. I have two thoughts that may be valuable for you.

1) You can do an extended pre-bolus before you eat. This gives you a chance the cancel the remaining insulin dose if you learn your meal will change for any reason n-minutes before or during your meal. Maybe the meal unexpectedly tastes bad, you can cancel the remaining insulin. Maybe the restaurant tells you they are out of the dish you order n-minutes ago. This is called different names in various insulin pumps; Extended bolus, temp basal, etc.

2) Pre-bolus and eat AFTER you see your blood glucose decrease for 3-4 readings. Pre-bolusing for static time like 15 minutes before eating does not work consistently because there are lots of variables at play before you eat that directly affect (a) insulin sensitivity and (b) blood glucose. (Environmental temperature, insulin temperature, injection site, adrenaline, stress, pain, previous meals, lipid levels, exercise, medications, illness, to name a few).

Eating after I see my BG decrease for at least three consecutive readings has helped me stay in range (70-140) for 95-100% of the time and maintain a healthy A1C (less than 5).

Cheers!

Same here, or more often I'll just wait to start eating if it comes early. I was selfconsious about it at first but staying in range is more important to me than any awquard feeling saying "please start, I just need to wait a few minutes", no one ever makes a fuss.