Can I estimate a food’s GI by looking at the ingredient listing or nutrition label?
We are often asked this question. And the simple answer is that you can’t ‘work it out’. A packaged food’s Nutrition Facts panel will tell you the carbohydrate content, but it won’t indicate the GI of that food. If it contains at least 10 grams of carbohydrates per serving, you can be sure it will have at least some effect on your blood glucose concentration – but there’s no way of telling whether it will be a little or a lot. Similarly, you can’t estimate the GI of a food by looking at its ingredient list, because it won’t tell you the final state of the starches in the food – which ultimately determine GI value. However, you can make some generalisations about the GI of different foods that you can keep in mind when shopping. Legumes, for example, have some of the lowest GI values whether you buy them dried or canned, it doesn’t matter about the brand. Most pasta and noodle products tend to be low GI foods too as are most fresh fruits and dairy foods like milk, yogurt, ice cream, and
