Given that protein appears to contribute to insulin demand I ran a number of scenarios with the food insulin index data to see if insulin requirement is better predicted by carbohydrate in a food plus some proportion of the protein.
The analysis indicates that insulin demand is related to carbohydrate about 60% of the protein.
There’s not a lot of information on the split between glucogenic amino acids and ketogenic amino acids out there, however it seems that only leucine and lysine are exclusively ketogenic and cannot be converted into sugar, while isolucine, threonine, phenylaline, tyrosine and tryptophan are both ketogenic and glucgoenic. The remaining thirteen of the twenty one amino acids are exclusively glucogenic, meaning that they can be converted to sugar.
The proportion of protein that can turn to glucose relates to the amount of excess protein to the body’s needs, so it will be affected by a number of factors including a person’s activity levels, how much protein and carbohydrates they eat.
The correlation of food insulin index with carbohydrate about half the protein is better than carbohydrate alone (R2 = 0.435 compared to R2 = 0.461) and we no longer have the issue of high protein foods sitting on the vertical axis as shown below.
Accounting for protein in addition to carbohydrate seems to better predict insulin demand.
So in summary, while protein doesn’t spike blood sugar as much as carbohydrates, protein does still require a significant amount of insulin. People not achieving the desired results from carbohydrate restriction alone may benefit from moderating their protein intake.
[next article… fibre… net carbs or total carbs?]
[this post is part of the insulin index series]
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