Glycemic Response of a Carbohydrate-Protein Bar with Ewe-Goat Whey

Functional foods are defined as “foods that, by virtue of the presence of physiologically-active components, provide a health benefit beyond basic nutrition’’.

As consumer interest in functional dietary items is increasing, there is a need to evaluate all physiologically active components and their role in health promotion.

During this study we examined the glycaemic index (GI) and glycaemic load (GL) of a functional food product which can be used in both everyday life and a sporting environment, which contains ewe-goat whey protein and carbohydrates in a 1:1 ratio.

How the Study Worked

9 healthy volunteers, (age, 23.3 ± 3.9 years; body mass index, 24.2 ± 4.1 kg·m2; body fat %, 18.6 ± 10.0) randomly consumed either a reference food or amount of the test food both with equal carbohydrate content in two visits.

In each visit, seven blood samples were collected; the first sample after an overnight fast and the remaining six at 15, 30, 45, 60, 90 and 120 min after the beginning of food consumption. Plasma glucose concentration was measured and the GI was determined by calculation of the incremental area under the curve.

The GL was calculated using the equation: test food GI/100 g available carbohydrates per test food serving.

Woman Eating a Protein Bar

Practical Application

  • The GI of the test food was found to be 5.18 ± 3.27, while the GL of one test food serving was 1.09 ± 0.68.


  • These results indicate that the tested product can be classified as a low GI (<55) and low GL (<10) food.


  • Given the health benefits of low glycaemic response foods and whey protein consumption, the tested food could potentially promote health beyond basic nutrition.


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