How insulin sensitivity and resistance can influence the amount of carbs you may want to consume
Here’s a recap on a study that showed how insulin sensitivity and resistance can influence the amount of carbs you may want to consume while on a calorie-restricted diet. However, before we go any further let me explain what being insulin sensitive and resistance means.
Insulin is a storage hormone released by the pancreas in response to food (with carbohydrates being a potent stimulator). When released, insulin travels through the bloodstream and attaches to receptors on cells, which allows nutrients to be absorbed. Think of the receptor as a keyhole and insulin as the key. When they connect/click, the “door opens” and nutrients can come in.
Depending on how responsive the cells are to insulin, one can be insulin sensitive or resistant. That is, if they are sensitive then their cells are receptive to insulin. Oppositely, if the body’s cells do not properly respond to insulin, they are resistant. Ok, so now that we’ve covered that, lets get back to the study.
In this research paper presented in the journal, Obesity Reviews, researchers studied the effects from varying carb and fat intake when on a calorie-restricted diet. To do so, they recruited obese, non-diabetic women (23-53 years old) who were either insulin sensitive (fasting insulin < 10 microU/mL) or resistant (fasting insulin > 15 microU/mL) and put them on one of two calorie-restricted diets: a lower or higher carb diet. The lower carb diet consisted of 40% carbs and 40% fat. The higher carb diet consisted of 60% carbs and 20% fat. The women followed this diet for 16 weeks.
Before and after the study, the researchers measured the body weight of all the subjects. Unfortunately, they did not measure fat mass. Regardless, after the 16 weeks, the researchers found that all subjects lost a significant amount of weight. Interestingly, those who were insulin sensitive following the higher carb intake lost significantly more weight than those who were also insulin sensitive and consuming the lower carb diet. Additionally, those who were insulin resistant and consuming a lower carb diet lost significantly more weight than those who were also insulin resistant, but following a higher carb diet. Also, worth noting is that those who were insulin sensitive and following a higher carb diet lost about the same amount of weight as those who were insulin resistant and consuming a lower carb diet.
Just keep in mind that this was one small study conducted on obese subjects, so this is not gospel and it would have been nice to see what effect this had on fat mass and fat-free mass. However, the results of this study suggest that insulin sensitivity may have an influence on the amount of carbs one should include in their diet.
For more information:
Cornier MA, et al. Insulin Sensitivity Determines the Effectiveness of Dietary Macronutrient Composition on Weight Loss in Obese Women. Obes Res. 2005 Apr;13(4):703-9.