Glycemic index is a measure of how fast carbohydrates increase blood sugar. Low-glycemic index foods are higher in complex carbohydrates and are broken down more slowly, while high-glycemic index foods are higher in simple sugars and break down quickly.
A study from Imperial College London found that low-glycemic index diets caused improvements in heart risk factors and blood flow regulation. Middle-aged subjects followed either a high- or low-glycemic index diet for six months. Those following the low-glycemic index diet showed 6 percent decreases in total cholesterol and LDL (bad cholesterol), an 18 percent decrease in triglycerides (blood fats), a 27 percent decrease in fasting insulin (controls blood sugar and fat storage), and an 11 percent decrease in 24-hour blood pressure.
There were no differences between groups in blood sugar levels or weight loss. Glycemic index of a weight-loss diet does not affect weight loss, but has significant health benefits. (Metabolism Clinical and Experimental, 58: 1703-1708, 2009)
