Low GI does not mean a food is healthy or efficient at supplying protein. Glycaemic index measures a blood sugar response under a set test. It does not measure protein quality, total calories or the value of a snack for your goal.
One useful number has been given far too many jobs. A low GI claim should answer a glucose question, not every nutrition question.
Know what the test measures
GI tests the rise in blood sugar after a set amount of digestible carbs. It compares that rise with a reference food. The portion used for testing is not always the portion you normally eat.
The amount of carbohydrate in your serving still matters. So does eating that food with other foods.
A low score does not tell you that a large serving has few calories. It also says nothing about how much protein those calories buy.
Look at the evidence in context
A review of trials in people with diabetes found better blood sugar control with lower GI or glycaemic load diets. Glycaemic load also accounts for the amount of carbs. That supports a role for the approach in that setting. [1]
It does not prove that every low GI protein bar is the best snack for an active person. The review tested whole diets and health results. It did not rank each bar on a shelf.
A separate review in people with overweight or obesity found little or no clear weight advantage from lower GI diets compared with other diets. [2]
Keep the protein job clear
A food with lots of fat still supplies plenty of energy even if its blood sugar response is low. A low GI number does not cancel that energy.
For a snack bought for protein, use the one to ten rule first. Divide calories by ten and check whether the protein grams reach that amount. Then assess the source, taste and price.
FEERO's focus is efficient protein delivery. Low GI is not a substitute for meeting that standard.
Use blood sugar details when they matter to your needs. Just do not let a narrow claim overrule the full label. A protein bar should earn praise for doing its main job, not for being good at a different test.