7 Bolusing for Meals

FreeAPS (FAX) does not actually give meal bolus recommendations as does Loop. Here’s what the Meals section of LoopAndLearn FreeAPS docs recommends:

The built-in function to give a bolus is not a bolus calculator in the same way as Loop has one, so don’t expect it to give you enough insulin.

It takes the insulinReq calculation and uses it to provide a bolus estimate. The insulinReq value is calculated based on a number of prediction curves, and when carbs are added, it mediates the effect of carbs with the other curves.

It’s not a bolus calculator. The insulinReq value is not necessarily as much insulin as the normal meal bolus would be (it’s conservative for safety reasons).

The recommendation with oref1 is to bolus 60%-75% of required meal bolus and leave the algorithm to deal with variation in absorption. This is the way most people use it.

7.1 Rule-of-Thumb Meal Bolusing

Rather than pull out a calculator, one pre-bolus strategy might be to form a rule-of-thumb scale for yourself like the following. You should make your own based on your needs and Carb Ratio (CR):

• Small meal 20g or less –> 2U
• Medium-size meal 20g-40g –> 3U
• Big meal 40g or more –> 4U

Your scale should be based upon your carb ratio and the % of upfront bolus that you prefer. For example, with a Carb Ratio of 10, the above meal boluses would provide a: * 100% upfront bolus for 20g * 75% upfront bolus for 40g, and * 67% upfront bolus for 60g

7.2 Let FAX-ng Do Its Work

With an appropriate pre-bolus and Settings, you should NOT need to issue manual boluses after your meal. This may be a difficult task coming from Loop!

If you used automatic bolus with Loop or the FreeAPS fork, youll find Temp Basal a little slower than you are used to, but its worth taking the time to test and adjust your settings before you turn on SMB/UAM.

Observe for a few days and make adjustments as needed so that you wont have to issue correction meal boluses.

(Thanks to LoopAndLearn for this.)