Glycemic Load (GL) been a useful concept in scientific research, and, on a practical level, can be useful for individuals with type 2 diabetes (who do not use insulin), as they are more reliant on modifying the foods they eat in order to control post-meal blood glucose spikes.

However, for individuals with type 1 diabetes (who, therefore, take insulin), the concept of Glycemic Index (GI) is more helpful in a direct way in terms of matching food to insulin action, and thereby controlling post-meal blood glucose spikes. The concept of Glycemic Load is helpful indirectly in that taking it into account can help us understand when more or less insulin may be needed to deal with post-meal spikes; glycemic load is the reason that many people with T1D report that, compared to a regular-sized meal, when they eat the same meal as a very large portion (say, twice as large) they need to give relatively much more insulin (more than the twice as much insulin that would be expected for this doubled portion-size).

Similarly, you may find that if your child eats a moderate amount of a given food (let’s use 1 cup of pasta as an example), the usual insulin-to-carb ratio (I:C) seems to work just fine; however, if he is ravenous one evening and eats much more than the usual amount (let’s say 3 cups of pasta), it may be that the usual I:C doesn’t provide enough insulin to avoid a high blood sugar following the meal. Assuming that the I:C is set correctly, this phenomenon may be explained by Glycemic Load: the glycemic index in both portions remains the same (it’s the same pasta in both scenarios), but the carb content of the larger portion is significantly higher, resulting in a higher “load” on the digestive system. Thus, proportionally more insulin may be required for a very large portion than for a smaller portion. (This doesn’t happen with everyone with type 1 and may be more pronounced in small children - a valuable reminder of the complexities involved with diabetes: two plus two rarely equals four when you’re living with the diabetes dragon!)

In short, if we already understand that both glycemic index and carb content affect blood glucose, then it's only a small step to knowing that the higher a meal is on either one of these components (that is, the higher the glycemic load is) the greater the effect will be on blood glucose. Being aware of this fact can help us adjust our approach to insulin delivery and (hopefully!) reduce post-meal blood glucose spikes.