You’ve probably seen it stamped on food packaging, and heard the buzz term on television ads for chocolate-studded breakfast bars: low GI.
What Does Low-GI Mean For Your Health?
The glycaemic index (GI) is a measure of how quickly a food raises blood sugar. It’s pretty simple really: simple sugars that don’t have any fibre, fat, or protein to slow their release spike the blood sugar; longer-chain carbohydrates – accompanied by all the other components of a whole food – release the sugar in to the blood at a slower and more even rate. GI is scored out of 100, with under 55 being considered “low GI”, 56 to 69 thought of as “medium GI”, and anything over that is high GI. The general consensus is that the lower the glycaemic index, the better a food is for you in terms of weight management, blood sugar swings, and pre-diabetes.
But can we rely on the glycaemic index as a measure of how healthy a food is? Is “low-GI” enough to give a food the tick of approval? Not quite.
Sure, GI gives us a good idea of the rate at which sugar floods our arteries, but it ignores how much carbohydrate there is in the particular food to begin with. Enter our new friend, “glycaemic load” (GL).
GL looks at the overall effect of a food on blood sugar in terms of it’s GI and the amount of carbohydrate it contains. And it reveals a few shockers. For example, nobody can rationally argue that a slice of watermelon is bad for you, but it has a whopping (and misleading) GI of 72. It’s GL? 3.6, where anything under ten is considered low. On the other hand, those gluten-free corn tortillas that boast a low-GI of 52, deliver a glycaemic load of 25. Anything above 20 is high GL, so 25 is a definite red flag.
Confused? It’s understandable. Navigating the waters of food packaging and health claims is tricky business, but you’ll notice that most of the low GL foods out there are the same whole food options we love. So keep it simple and JERF – just eat real food.