Glycemic index diets: More lentils, less mushy white bread. July 19, 2007

July 19, 2007 By Grendel Burrell [mailto:grendel.burrell@gmail.com]

While no one says that weight loss is easy, consumption of beans, whole grain bread and non-sugar cereals (termed low glycemic index foods) may make the diet process easier or at least more rewarding. Low glycemic index foods are a more consistent source of glucose to the bloodstream and thus stimulate less insulin release than foods with higher glycemic indices such as white bread, white rice, soft drinks, and high sugar items. Even in situations when the total caloric intake is the same, low glycemic index foods may stimulate weight loss in overweight or obese individuals. “In my practice, about 65% of patients are overweight or obese, and given the prevalence of metabolic syndrome, and insulin resistance, I instruct patients on ways to incorporate these foods into their daily diet”, commented Joanne Foody, MD, Associate Professor and Director of Cardiovascular Education, Yale University School of Medicine.



In the July 18 issue of the Cochrane Review, Dr. Diana Thomas and colleagues from the University of Sydney analyzed six randomized controlled trials comparing low glycemic index diets with high glycemic index diets or conventional weight-loss diets. 202 overweight or obese subjects participated in the trials that ranged in length from 5 weeks to 6 months. Follow up varied in length up to 6 months. The studies did not report adverse events, mortality or any quality of life data (Thomas DE, et al "Low glycaemic index or low glycaemic load diets for overweight and obesity (Review)" Cochrane Library 2007: CD005105. doi: 10.1002/14651858.CD005105.pub2. ).

Decreases in total cholesterol and LDL-cholesterol were greater for the low glycemic index diets compared to the standard diets. Participants who followed the low glycemic index diets lost a mean of 1 kg more than those on the high glycemic on conventional diets. A mean weight loss of 7kg was reported. The participants in the low glycemic index diets also had significantly larger decreases in body mass, total fat mass, and body mass index compared to participants in the other diet groups (Thomas DE, et al "Low glycaemic index or low glycaemic load diets for overweight and obesity (Review)" Cochrane Library 2007: CD005105. doi: 10.1002/14651858.CD005105.pub2. ).

When WikiDoc questioned Dr. Foody about the clinical significance of a 7 kg weight loss, she stated, “A 7kg weight loss will translate into about 10 mm decrease in systolic blood pressure, will reduce insulin resistance and blood sugar, will improve lipid profiles and will certainly improve self-efficacy and self-esteem.”

“All diets are somewhat confusing to patients but if you explain to people that you are reducing surges in sugar, they seem to understand,” said Foody. This instruction, coupled with the real improvements in critical indices may make a difference. However, if adherent with diet, about 75% of patients can have sustained weight loss. In patients who are committed to this diet, i.e. a ‘South Beach’ type diet, they have benefits of weight loss, reductions in BP as well as important shifts in lipids,” she commented. The South Beach diet was developed by cardiologist, Dr. Arthur Agatston, and can be found at this web address, http://www.southbeach-diet-plan.com/glycemicfoodchart.htm. A quick Google search for Dr. Arthur Agtston will provide tens of thousands of links. Additionally, a good source of foods and glycemic indices is located at http://www.lowglycemicdiet.com/gifoodlist.html.

Thomas DE, et al "Low glycaemic index or low glycaemic load diets for overweight and obesity (Review)" Cochrane Library 2007: CD005105. doi: 10.1002/14651858.CD005105.pub2.