Basal/Bolus Balance

Basal/bolus balance is how much of your TDD goes to basal rates and how much goes to boluses. In clinical studies, basal rates average 48% to 54% of the TDD. Various factors affect this balance. Someone on a high carb diet will use a larger portion of their TDD for carb boluses and a smaller percentage for basal rates, while someone on a low carb diet would use a higher percentage of their TDD as basal. Basal percentage also varies by age and weight. The basal percentage tends to be lower in children prior to puberty and in lean older adults. Children and adults who were recently diagnosed often retain some insulin production and may do well at first with less than 40% of their TDD as basal.

How Much Do You Need?

10.8 Common Basal Percentages of TDD
40-44% Kids and adults who are sensitive to insulin, physically fit, on a high carb diet, or have residual insulin production in first 5 years after diagnosis.
45-60% Most people
60% or more Adults or teens on a low carb diet or who often miss carb boluses.

Although there are no perfect answers, almost all Type 1s, and most people with Type 2, on insulin find their control is best when their long-acting insulin (Lente, NPH, Ultralente, or the basal rate on a pump) makes up 55% to 60% of their total daily insulin dose. This level lets you skip meals, and still keep your blood sugars relatively level.

How Do I Tell?

First determine your Total Daily Insulin Dose (TDD)
H or R L/N/UL
Breakfast ___ units ___ units
Lunch ___ units ___ units
Dinner ___ units ___ units
Bedtime ___ units ___ units
Subtotal ___ units ___ units = A
TDD ___ units = B

Then divide your total long-acting insulin (answer A) by your TDD (answer B):

A / B = ____% as your Basal/Bolus Balance

Critical question: How close is your own TDD to 55% to 60%?