With certain assumptions, one would expect total daily dose (TDD) to be proportional to bodyweight. Thus is it perfectly normal for a petite woman weighing 100lbs to have half the total TDD of a 200 lb man. Couple that in with other variations, including being young and insulin sensitive, having residual insulin production, being physically active and eating a reasonably modest level of carbs and you can see how someone might have a low TDD. Usually, one would have a split of your basal and bolus of about 50-60%. If you are low carbing (ala Dr. B) and heavily tilted towards a dominant basal dosing, your low insulin requirements are probably partly a benefit of the low carb regime.
Certainly with your insulin sensitivity, it is easy to see how the finer dosing available with a pump probably made a big difference. Although insulin today is all the standard U-100 strength, historically there had been weaker strengths on the market (U-40 and U-80). For very insulin sensitive children some doctors still recommend dilution of insulin, which should you ever consider going back to MDI (I don’t know why you ever would) would be an option that would let you obtain finer control.
Still, there are so many that struggle with insulin resistance and much higher insulin requirements, you certainly should not worry about things, instead you should just do a happy dance.
