Glycemic Index - Weight Control

Weight Control

Recent animal research provides compelling evidence that high-GI carbohydrate is associated with increased risk of obesity. In one study, male rats were split into high- and low-GI groups over 18 weeks while mean body weight was maintained. Rats fed the high-GI diet were 71% fatter and had 8% less lean body mass than the low-GI group. Postmeal glycemia and insulin levels were significantly higher, and plasma triglycerides were threefold greater in the high-GI-fed rats. Furthermore, pancreatic islet cells suffered "severely disorganised architecture and extensive fibrosis." However, the GI of these diets was not experimentally determined. Because high-amylose cornstarch (the major component of the assumed low-GI diet) contains large amounts of resistant starch, which is not digested and absorbed as glucose, the lower glycemic response and possibly the beneficial effects can be attributed to lower energy density and fermentation products of the resistant starch, rather than the GI.

In humans, a 2012 study shows that, after weight loss, the energy expenditure is higher on a low-glycemic index diet than on a low-fat diet (but lower than on the Atkins diet). See also news coverage and reactions from other obesity researchers.