December 29, 2014
Does the Glycemic Index Matter?
This is one study that goes against many studies, and being a small study – 163 overweight people divided into four groups – does not prove what they wanted to prove. The reason is there are too many variables that are not accounted for and they pushed conclusions that may not have been accurately accounted for in the study.
Yes, low glycemic index foods may not have resulted in greater weight loss, but even in the study details which I was able to acquire, the low glycemic index foods were not revealed.
I do not appreciate that even what they consider healthy foods are not detailed. Some low glycemic foods can be unhealthy and not telling what low glycemic foods were used is just as bad as not stating what healthy foods were used.
I could believe that may of the foods used were from the foods promoted by the USDA and this statement does call this into question, “In fact, researchers found that overweight adults placed on a low-GI diet actually showed less sensitivity to insulin than those on a high-GI diet. Insulin is the body's key blood-sugar-regulating hormone, and a decline in insulin sensitivity can eventually lead to type 2 diabetes.”
When a researcher says, "Low-GI diets are difficult to follow," I can believe this, as they are not as nutritious as the foods in a higher-GI diet. Then this statement points to possibly the reason for this research, "If you don't have to worry about foods' glycemic index, that makes it easier to follow a healthy diet." Don't get me wrong, the glycemic index isn't the end-all, but can provide some pointers that help people avoid diabetes or delay the onset of diabetes.
What annoyed me was that all of the diets were based on the DASH diet ((Dietary Approaches to Stop Hypertension) which is supposedly a heart-healthy plan that is built around fruits and vegetables, fiber-rich grains, 'good fats like olive oil, fish, and low-fat dairy products. Then they varied the number of carbohydrates to distinguish the different diets, either 58 percent or 40 percent of daily calories, and finally either high or low in glycemic index.
The variable was added after five weeks when the study volunteers were switched to a different diet of the four diets. By not saying which, the results could have been easily swayed the way the researchers desired. All of the participants were required to eat their main meal at the research center and then given their other meals and snacks to take home.
By not saying which diets and which they were switched to at the end of the first five weeks, they then claim the results showed some surprises. They claimed that the high-carb, high-GI diet had the greatest results in insulin sensitivity. In contrast, the people's insulin sensitivity barely changed when they followed the high-carb/low-GI diet, the study reported. None of the participants had diabetes according to the researchers.