This assumes a Lantus / Humolog Sliding Scale Regimen

>Can you please give me some insight into what to expect from insulin on BG compliance after meals? This assumes a Lantus / Humolog sliding scale regimen.<

First, the term "sliding scale" may not be the most accurate description that you're looking for. If you're counting grams of carbohydrate and basing your dose of Humalog on how many grams you're going to be eating, that's not a "sliding scale," it's using an insulin to carbohydrate ratio, and the two terms really aren't interchangeable -- one's a far less reliable method since a "sliding scale" never takes food to be eaten into consideration; it simply takes BG before a meal into consideration and gives you ranges (i.e., 200-250, take "X" units; 251-300, take "X" units, etc.) Sliding scale is inherently flawed at its core since there is NO way to maintain reasonable BGs after meals if the food to be eaten is not part of the calculation. You will always rise if you eat; how high, depends, of course, not only on how many grams of carb you're eating, but on what TYPE of carbs you're eating. What you're talking about is "MDI," or multiple daily injection therapy, if you're talking about different doses based on both pre-meal BG (where the correction or sensitivity factor comes into play; that's what you were talking about with one unit dropping you by 'X' and determing how much to use to get to our target BG BEFORE adding in the variable of the food to be eaten) and carbohydrates and even some portion of protein in some cases to be eaten. The pump separates these into two different "doses." My friend uses an Animas pump, and they're referred to as "ezBG" -- the correction factor, which is set and stored and varied throughout the day -- and "ezCarb," where the I:C ratios are stored, and can be also, and often is, varied throughout the day. But I'm veering too far from your basic question.

>I am curious how high BG should be expected to spike post prandial (say at one and two hours). How long should it take for BG to return to 120 or less after a meal assuming Lantus is doing its job and maintaining 120 or less for a fasting BG.?<

It's hard to say and is based on so many variables. If you eat a meal containing 35 or 40 grams of carbohydrate and a good portion of those carbs are from green, non-starchy veggies, you're not going to experience the same dramatic PP rise that you would if those 35 or 40 grams came from a starch. Some foods spike my BG very quickly and very high, and others are slower in the rise. The I:C ratio may also need to be adjusted if most of the carbs in the meal are veggie carbs; you may not need as much to cover those carbs since they're naturally far lower glycemic than a starch. The only starch that I eat is bread -- I don't eat rice or potatoes, except in very very occasional measured tiny amounts (an ounce or two of rice), and even more rarely eat pasta, but starches naturally have a significant effect on me, where veggies are much more stabilizing and need less Novolog at meal time. You need to look at what you're eating, how much you're eating, where you're starting the meal BG-wise, how much lead time you've given the insulin that you're taking for that meal, whether you have an accurate carb count or it's an estimate, and so on. For ME, I can peak dramatically at hour 1 (my "peak" was found to be at 75 minutes for most meals that didn't contain a lot of fat that might slow down the process of the peak), be still-elevated at 2 hours, and be back to baseline and still falling by hours 3 and 4.

>I understand Humolog is supposed to be all gone after three hours, but I am seeing some screwy effects that make me wonder about that.<

That's the standard formal information that is given, but that can and does vary for many people. For me, it lasts up to 4 or 5 hours; for my insulin sensitive T1 friend, it can still affect her 6 hours out of a meal bolus. It also depends on time of day. I find that my Novolog lasts longer and has the ability to drop me longer after the lunch bolus than it does after breakfast or dinner. I sometimes find that the drop between hours 3 and 4 is the MOST dramatic drop that I see, which is what is typically well beyond the insulin's supposed "peak" time. You and I are individuals and we're different. What I've described might not be at all like your own circumstances. The best advice would be to eat a simple, clean diet for a few days and test around your meals to see where you are at specific times, and how far you drop the farther away from the start of the dose you are.