What is the right method for Extended Bolusing?

So, I just got a Tandem T Slim Pump hooked up today to help being T1. Everybody says one of the cool things about it is that you can do extended bolusing. However, through searching the forum and provided info I cannot find out how I should properly be doing an extended bolus! Could somebody explain this to me? I am sure there must be some helpful equation to figure it out that I don't know about.

I am currently on a low-carb, high protein diet. I get all my carbs from veggies or fruits and typically eat around 15g with each meal. Protein might be as high as 20-30g per meal of most often lean meats. I know that an extended bolus can help with a diet like this but I am not sure what percentages or what duration to use. Plus I have heard the amount of fat in the meal can be a big factor...? I know I will have to play around with it a bit to really get it right but does anybody have any starting advice to test with?


The basic TAG approach works well for me when I have a high protein low carb meal.

Firgure the "carbs" as whatever actual carbs are in the meal, plus 50% of the protein weight. For example, a meal with 15g carb and 30g protein would bolus like 15 + 30/2 = 30g of pure carb.

Then, set your bolus to deliver the carb portion immediately, and the protein portion over 2-3 hours ( I use 2.5 hours) in a square bolus.

It doesn't need to be any more complicated than that.

Dave mentioned a good starting point, but it can be different for everyone, especially for those who have diabetes a long time, and may have digestion issues. Activity level can also influence how slow/fast your food is digesting, and hitting your BG.

Be your own science experiment. If you go low 1-2 hours after a meal, you might need to split/extend your bolus. If you are going high 3-4 hours after meal (high fat/protein meal), you might need to add more to your bolus, but extend it.

It’s all about trial and error.
I can eat pizza if I use a combo bolus.
That is a regular bolus and extended too.
I take 30 percent 15 min before I eat and do extended for 70 percent over 2 hours.
I use this method for pretty much anything that has heavy carb and heavy fat.
Which of course should be never. But we all have to cut loose sometimes.
Anyway try a few different combos and lengths of time. I think 2 hours is a good starting point

I learned by trial and error. I use an extended bolus when I eat french fries or high fat foods. That being said, even french fries vary. From McD's I take 95% right away and then the last 5% over 30 minutes. That keeps the bs in good ranges. For Wendy's...I can't do that. I guess they have a bunch more fat, but they are 40% right away 60% over 30 minutes. I tried the 95/5 for them and crashed every time I did it.

I have never seen the TAG approach. Might have to try it.

Overall, I think it's something you will need to figure out for your body and what foods you eat. Good luck!

I've played around with it and Dave's approach seems very sound but, for the most part, I find that bolusing away and cutting basal if it runs low works better than extended boluses. The only food I really notice taking a while to digest is pasta and I don't eat that very often. I'm the cook and the shopper so, well, it doesn't get on the menu very often! For stuff like cocktail parties where I'm eating for an extended period of time, I prefer to just bolus for what I eat, or fire chunks of insulin and eat and drink to catch up to it, after I scout out what's available to munch on.

I learned the TAG method here a few years ago. I eat a low carb diet, about 50-70 grams per day. I give an extended bolus for every meal.

The way I do it is to simply give the carb bolus up front like most of us do.

Then I add 50% of the meal's protein grams to 10% of the fat grams and divide that total by my insulin to carb ratio (I:C). The 50% and 10% figures I arrived at were through trial and error and work for me. Your experience may differ!

For example if I eat 24 grams of protein and 30 grams of fat then I calculate (24 x 50%) + (30 x 10%) = 12 + 3 = 15 grams of carb equivalents. If my I:C is 1:5, then I figure 15/5 = 3.

I then use the extended bolus feature on my pump to deliver 3 units over time. Some comments in the TAG group found that the extended boluses seemed to perform best for them when they delivered about 0.8-1.2 units/hour. So in this example I would deliver 3 units over 3 hours for a 1.0 units/hour rate.

I don't use the percentage split between the immediate and extended bolus portions. It makes the math unnecessarily complicated.

My extended boluses are as short as 1 hour and as long as 6 hours. I only eat two meals per day. This system works very well for me. You'll have to do your own experiment to discover your optimum system.

It's not as complicated as it at first appears. I've found it to be highly effective to smooth out my daily CGM lines.

By the way I weighed all my food portions on a gram scale to get an accurate count. I use Calorie King to convert the weight to grams of carb, fat, and protein. The less SWAG the better the post meal BGs!