# Bolusing for fat and protein

I've started accounting for fat and protein in my bolus calcs as discussed in that TuD group I can't remember. Basically, total the grams of fat and protein, divide by 2, add as additional "carbs" to the bolus calc, then do an extended on that extra juice.

I extend it for 2-3 hours usually, depending on the size of the meal.

Now, the main point of this post: If you're using percentage as the means to specify the break between immediate and extended bolus, it can get a bit annoying to try and figure it out on the fly.

So, I did some surveying of fast-food nutrition menus and worked up a spreadsheet to see what the ratios are for carbs vs. 50% by weight fat+protein. I used fast food only because the detailed nutrition information is readily available.

The key point: What I found is the ratio between insulin for the meal carbs, and insulin for the fat+protein generally runs between 60-80% carb.
This was across a wide range of menu items, from Taco Bell regular tacos to Burger King whoppers. Same for healthier fare, like TB's fresco chicken soft taco. Salads that contained meat were in the same ballpark.

BOTTOM LINE: A quite good rule of thumb comes out of this. First, if you know or can estimate the carbs in an "ordinary" meal, you can conservatively approximate the extra carb equivalent insulin need from the fat+protein at 1:4 to 1:3. Then, simply deliver 75-80% of the total bolus immediately, extending the balance for 2-3 hours.

Example: Meal has 24g carb, 20g fat, 16g protein (2 crunchy tacos at TB). Total "carb equivalence" would be 24+20/2+16/2 = 42g. Actual carbs are 24/42 = 57%. So, bolus for 42g, use extended bolus with immediately delivery of 60% (omnipod only supports 5% increments).

The approximate way for this same meal would be 24g carb; using the 1:3 rule of thumb, there's roughly another 8g "carb-equivalent" BG loading from the fat and protein, slow digested. So, bolus for 32g, deliver 75% initially, extend the rest for 2 hours.

I've been doing this now for a week, and my control is quite a bit better! I am flirting with lows more, so some experiment/learn/adjust is necessary as I work this out.

Thought I share this with people who are having trouble getting their BG down after meals, even when the count carbs and do everything right. Fat and protein get converted to glucose to some degree by the liver, so not accounting for this may be the reason your sugars don't come all the way back down after eating, and you have to correct.

With that, I'm off to go have two Taco Bell crunchy tacos for lunch

Adding insulin for proteins and carbohydrates is a highly debated topic because it can lead to better control but you really have to be careful so that you don't start having more lows. I work in a diabetes clinic and I have been able to do some research on this for myself and hopeful for our patients. There is yet to be a definitive answer but we do know that protein does raise blood sugar and fat slow down carbohydrate absorption.

Back in the early 1900's there was a lot of research on this and the potential for protein to turn into glucose. Theoretically about 50% of protein can become carbohydrates, based on proteins composition of amino acids. Problem is, there has been no evidence in normal individuals or in diabetics that 50% of the proteins you eat become carbohydrates. It largely depends on whether the patient is fed or fasted, the composition of the meal and in diabetics their state of insulination. The fact is that protein may become carbohydrates but the bigger problem may be related to alpha cell dysfunction.

As we know with T1DM a persons beta cells are slowly killed off and we can not produce insulin. Our alpha cells or the ones that produce glucagon are still there. When you eat protein, full proteins or even certain amino acids, it stimulates your pancreas to secrete insulin and glucagon. Well with a T1Dm you don't secrete insulin anymore so this rise in glucagon can stimulate release of stored glucose and without extra insulin to prevent this your blood sugar can go high. So in reality you likely need the extra insulin to prevent the liver from producing and releasing glucose along with release of glucose from muscle tissue rather than for the protein itself becoming glucose. How much is hard to tell and it also largely depends on the amount of carbohydrate you eat with the protein. As the ratio of grams of protein to grams of carbohydrate in a meal increases there seems to be larger secretion of glucagon and an increased need for the extra insulin. So when you eat a large steak or for some of you doing the low carb intake thing this might be very relevant to you but if you just eat a bowl of pasta with meat sauce you likely won't notice much of an impact from the meat. Each person is going to be different so as that protein rises consider adding more insulin.

Fat does not produce any rise in glucose due to fat turning into glucose. It does slow gastric emptying and increases insulin resistance. With that in mind a meal higher in fat (>40% calories of a meal from fat) would call for an extended bolus but not necessarily additional insulin. When you give a normal bolus with a high fat meal the rise in glucose is due to the delayed entry of carbs into the blood stream and by that point the insulin is wearing off. Worry more about the extra insulin for the protein and then extending it with more fat. Sorry for the long answer but I hope it helps.

The tuD group that you are probably referring to is the group called "TAGgers United." TAG stands for Total Available Glucose and the basic methodology is to count all net carbs, 50% of protein and 15% of fat as carbs (please someone correct me if I got this wrong). In your example, that would be 24g + 50% * 16g + 15% * 20g = 35g counted carbs.

Dr. Bernstein for years has used a similar way of accounting for protein. Particularly for low carb diets, the glucose load from protein may actually be more significant than the few carbs you ear. Bernstein also counts half of protein as carbs, but he considers fat as "free."

ps. Another key problem with high protein/fat meals is that your insulin may peak before the meal peak, causing your insulin to "miss" the meal and that you will have highs 3-5 hours after your bolus/meal.

Taco Bell tacos were the first meal I got with my pump. I wanted the other taqueria but had already been gone from work for a while and it was right there!

I am too lazy to do math as my pump does it most of the time. For protein/fat, I generally add 5G for moderate protein and 10 for larger amounts, maybe 15 for a really large hunk but I don't eat those very often and, when I do, I generally end up eating 1/2 and covering the rest with some dessert or beer or something horrible.

My dosing protocol is based on the TAGers United discussions here on TuD. I experimented with different conversion factors for protein and fat but I maintained the extended bolus feature that I found there.

I use a spreadsheet to claculate my dose when I’m at home. I count 50% of my protein grams as equivalent carbs and 10% of my fat grams. I don’t use the combo bolus with its confusing percentages. Instead I calculate the carbs separately and deliver that bolus immediately.

I then claculate my protein/fat bolus and deliver it over time. I limit the extended rate to a maximum of 1.2 units per hour. For example, if I needed to deliver 4.8 units for the extended protein/fat part of my meal, I would divide 4.8 by 1.2 to calculate the deliery time in hours. Therefore I would deliver 4.8 units over 4 hours @ 1.2 units per hour.

This works for me but I limit my daily carb intake to about 50-70 grams per day. I say this because it’s my understanding that with limited carbs the body will be forced to convert some of the protein to glucose. If you eat a meal with abundant carbs then your body may not convert much of the protein to glucose.

I’ve been using this system (low carb and extended bolusing for protein/fat) for about 18 months and it has worked quite well. I’ve been able to drop moy A1c by almost a full point, lost 23 pounds, and reduced my total daily dose of insuln by 50%. My Bg variability has also dropped considerably.