Using GL to sort the good, the bad and the suicidal 123 While not all doctors agree with this theory some very recent research on rats published in the highly respected medical journal, the Lancet, gives solid support to this argument. 21 The study could not be done as precisely on humans because the two groups needed to be given exactly the same number of calories and research shows, as we discussed in Chapter 5, that humans have a bad habit of sneaking food in any but the shortest of restricted food experiments! The researchers gave one group of rats low GI foods and the other group high GI while giving both groups exactly the same amount of energy. When they examined the two groups they found that the rats on the high GI diet had higher levels of body fat, elevated triglycerides and early stage diabetes. Many people are surprised to hear that increased carbohydrate intake actually increases the amount of fat circulating in our blood! This experiment explains exactly what is happening at a population level as we eat less fat and more carbohydrate while obesity and diabetes rates skyrocket. Another very high-powered study on GI was recently published in the American Journal of Clinical Nutrition. 22 In this study, 235 postmenopausal women were followed for three years and then, rather invasively, the arteries around their hearts were examined by injecting dye into their bloodstream and taking x-rays to see exactly what condition they were in. They found that women on the higher GI diets had worse hearts than those on low GI diets with higher fat intakes! We have to be careful 21 DB Pawlak, JA Kushner, DS Ludwig. Effects of dietary glycaemic index on adiposity, glucose homoeostasis, and plasma lipids in animals. The Lancet. London, 2004. 364; 9436; 778-85. 22 D Mozaffarian, EB Rimm, DM Herrington. Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women. American Journal of Clinical Nutrition, Vol. 80, No. 5, 1175-1184, November 2004.