Low-GI diet improves weight loss, glycemia in Type 2 diabetes
MedWire News: Study results suggest that following a low glycemic index (GI) diet significantly improves weight loss in patients with Type 2 diabetes, which subsequently leads to better glycemic control.
Writing in the Journal of Nutrition, Gabrielle Turner-McGrievy (University of North Carolina, Chapel Hill, USA) and colleagues carried out a 22-week study in which 99 individuals with Type 2 diabetes were randomly assigned to follow a low-fat, low-GI vegan diet (n=49), or a an individualized American Diabetes Association (ADA) diet (n=50) based on body weight and plasma lipids.
The researchers assessed the relationship between GI and glycemic load (GL), and degree of weight loss and glycated hemoglobin (HbA1c) reduction achieved by the participants.
They found that diabetics who followed the vegan diet achieved significantly lower dietary GI (-5.4) than those who followed the ADA diet (-1.7), but that the reverse was true for GL. The ADA diet group had a 37.4 point reduction in GL compared with an increase of 9.5 points in the vegan group.
Dietary GI, but not GL, significantly predicted weight loss. Following adjustment for changes in fiber, carbohydrate, fat, alcohol, energy intake, steps per day, diet group, and demographics, each point decrease in dietary GI was associated with an approximate 0.2-kg reduction in body weight.
Reduction in GI also initially predicted decreased HbA1c levels, but this association disappeared after adjustment for weight loss, which was a significant predictor for HbA1c reduction. Changes in GL were not related to HbA1c.
Turner-McGrievy and team write that "consumption of low-GI foods, but not a low- GL diet, appears to be one of the determinants of success of vegan or ADA diets in reducing HbA1c and body weight."
They suggest: "Additional studies to lower the dietary GI further than was accomplished in the present study by specifically incorporating low-GI foods, such as peas, beans, and lentils, would be of interest to examine the extent to which they can demonstrate further improvements in the metabolic advantages of therapeutic diets."
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By Helen Albert