A low GI diet may not help your blood sugar
Even though diabetes nutrition guidelines tend to advocate a low-glycemic diet, eating this way may not actually help improve insulin sensitivity, a study published in JAMA reports.
Furthermore, carbohydrate consumption seemed to change how glycemic load can affect insulin levels - and not in the way most people would assume.
For the study, researchers from Brigham and Women's Hospital and Harvard Medical School recruited 163 overweight adults. The participants were given one of four different diets: 1) a high-glycemic index and high- carbohydrate diet; 2) a low glycemic-index diet; 3) a high-glycemic index and low-carbohydrate diet; or 4) a low-glycemic index and low-carbohydrate diet.
As the researchers might expect, insulin sensitivity improved more in patients who ate high-carbohydrate, low-glycemic index foods than in those who ate a high-carbohydrate, high-glycemic index diet. Yet for patients eating a low-carbohydrate diet, it didn't seem to matter if they were in the high- or low-glycemic index group: insulin levels were not affected.
The biggest surprise, however, was the the low-glycemic index, low-carbohydrate diet didn't change insulin response when compared with the high-glycemic index, high-carbohydrate diet.
The main takeaway, researchers said, is that glycemic load may be less important of a factor in managing blood sugar than previously thought.
"In the context of an overall DASH-type diet, using glycemic index to select specific foods may not improve cardiovascular risk factors or insulin resistance," the authors said.
Source: JAMA Network