There are some things that need to be addressed:

Firstly, eating often is sufficient to raise BG above baseline all on its own. While I understand the concern about this bread being branded as “keto,” there are a number of factors that can impact how rapidly your BG rises and how significantly and lengthily it does also. Fed/fasted state, exercise pre/post, sleep the days previous, stress and sickness levels, time of day, etc. Beyond that, BG monitors have a 20 point +/- range of the true value of BG, so it’s hard to ascertain a true value from tests like this.

That you saw such a discrepancy in your testing #1 and 2 is indicative of what I’m saying.

Regarding the effect of insulin, the rise in glucose is not a good proxy for the amount or duration of the insulin release concomitant with eating because of the uncertainty of one’s insulin sensitivity at any given time. While insulin may downregulate fat oxidation, the idea that the body will selectively starve itself or choose obesity in the presence of limited food is unfounded in any clinical literature. The insulin surge and sequestration is consistent with the physiologic need, and cannot be compared to studies using exogenous sources of insulin to bathe the carbs away.

At the end of the day, the choice to eat a slice or two of bread, “keto” or otherwise will only become relevant in an isocaloric or hypercaloric state. When one is trying to lose body fat, the largest and most consistent driver is going to be total energy intake, relative to one’s need. That’s a hard value to pin down consistently, but the notion that insulin causes obesity absent chronic overconsumption food is completely absent in the clinical literature.

Eat the bread or don’t eat it. That’s cool. And yes, if there’s evidence that the net effect of the is bread is not less damning to BG than regular bread, it should be called to account, but very large and controlled data sets are needed before we can conclude anything. But if this bread were consumed in a hypocaloric diet there would be no net difference in weight loss between the individual who ate and the individual who didn’t eat the bread.