It is not uncommon to have modest increases of basal on low carb. I think this is for two reasons. First, protein may be digested over many hours and rapid insulin may wear off too quickly and you may depend more on your basal to cover your meals. And second, low carb will increase the production of glucose in your liver and that may require additional basal. Most people find that overall, while there may be some increase in basal, the bolus and total daily dose fall with low carb.
I completely revamped my basals not too long after I started to low carb. This involved about two weeks of basal testing. My basal rates were all reduced from what they were previously. I don't depend on my basal rate to cover any of my nutrition, including protein.
I bolus for protein and fat by adding their grams together and multiplying by 0.3. This accounts for the fact that not all of protein and fat are converted to glucose (gluconeogenesis). Then I take this amount and divide it by my current insulin to carb ratio. Since the glucose generated from protein and fat takes much longer than carbs to metabolize, I use a square wave (aka combination or extended bolus) bolus with the maximum rate of 1.2 units per hour. A typical square wave meal bolus for me lasts 3-4 hours. All the above numbers are customized for me using trial and error and guided by my post-meal meter readings. Your numbers and diabetes will vary!
It looks more complicated than it is once you get used to the routine. It would be nice if the pump companies started to incorporate some of this math into their hardware but I don't mind doing the numbers. It reminds me about how I did all the math before the pumps included a bolus wizard.
Tabacblond, here's a link to a study on the impact of fat in those with type 1 diabetes. Fat and protein intake naturally increase as one decreases carbohydrate intake.
They didn't test low carb, but it would make for an interesting study, I think.
I agree, adjust your basal rates first. Or maybe start by testing your basal rate before you make any big changes in any area. I really like Leo’s take on the 30 point margin. I will be working on this too… .
Thanks for posting a link to this current (published April 2013 in Diabetes Care) study. It mentioned that a previous study developed a formula for dosing insulin based not only on using carbohydrates but also including fats and protein. It noted that this formula has not been vetted using a crossover study. It added that the current study “showed no relationship between carbohydrate-to-insulin ratio and the need for more insulin to cover the HF [high fat] meal.”
I find it interesting that researchers have noted that simple carbohydrate dosing does not give good consistent postprandial BGs. I’m glad that science is finally catching up with we PWDs have known for a long time.
Wow, thanks for this great description. It gives me a starting place as I too am considering returning to a lower carb diet.
I was eating lower carb (and lower everything) while away from home for a week. I had to reduce my basal by about 10%, ran much lower than usual but quite stable once I reduced the basal - so i was comfortable running 85-95 most if the time. I did eat a few carbs so I bolused for each meal, but did not bolus for protein or fat.
I don't really understand why this is taking them so long to realize that :-)
This is such a small and uncontrolled study it is very hard to interpret any conclusions from this. I think many of us would agree that eating fat has an effect, traditional exchange diets and the Total Available Glucose (TAG) bolus for fat (TAG counts 15% of fat as carb equivalents).
I guess I just have to say "so what." If I eat a head of lettuce, I have to bolus for like 5-10 times the carb count. Blood sugar rise is complicated.
ps. One has to realize this is from Howard Wolpert who is one of the major figures entrenched into the "high carb" camp. Check out this debate between him and Bernstein on what good control means.