Is the Glycemic Index Important?

What is the Glycemic Index (GI)


The Glycemic Index is a tool which indicates a carbohydrates effect on blood sugar levels. Food is ranked as being very low, low, medium or high in their GI value.


Do you need to worry about the Glycemic Index?


It is suggested that the likelihood of developing certain chronic diseases may be avoided by simply choosing whole foods which have a low or very low GI.

Sacks et al. (2014) undertook a study to determine the effect of glycemic index and amount of total dietary carbohydrate on risk factors for cardiovascular disease and diabetes. The researchers conducted randomized crossover-controlled feeding trial, in which 163 overweight prehypertension adults were given 4 complete heart-healthy diets to follow for 5 weeks. The participants completed at least 2 diets.


One diet included high carbohydrate foods that are high on the glycemic index. A second diet included high-carbohydrate, low-glycemic food. A third included low-carbohydrate, high-glycemic food. The final include low-carbohydrate, low-glycemic food.


What Did the Study Find?


The study found that diets with a low glycemic index of dietary carbohydrate, compared with the high glycemic index of dietary carbohydrate, did not result in improvements in insulin sensitivity, lipid levels, or systolic blood pressure.


The researchers found that a low GI diet did not increase insulin sensitivity, but instead, it decreased it.


Dr Sacks, Professor of Cardiovascular Disease Prevention, Department of Nutrition, Harvard School of Public Health and also Professor of Medicine at Harvard Medical School, suggests it is possible that our bodies can handle foods which vary in glycemic index- even if they are overweight and are already having problems with insulin resistance.


The researchers indicate that from the results, a low GI diet may be more beneficial for individuals who are diabetic. However, more research needs to be conducted.


What Should You Do?


Avoid getting too caught up with the Glycemic Index of foods as it can get complicated.

Therefore, it is not necessarily about following a low GI diet it is more about following a healthy diet.


Tips to Manage Insulin Resistance

Insulin resistance can be managed, a common misconception about how to treat insulin resistance is by eliminating carbohydrates, however, while you may think you are treating it, you are not getting to the root cause.

Reduce Fat Intake

Research results suggest that reduce fat intake can help improve insulin sensitivity. A study found that reducing fat consumption from an average of 54 grams per day to an average of 27 grams per day allows your insulin to function properly again and in turn increasing insulin sensitivity.


Studies have found that while all forms of exercise can increase insulin sensitivity, resistance training can provide even more benefits as a result of the increase in lean tissue, in turn increasing your overall demand for energy. Researchers have found that each 10% increase in muscle was associated with an 11% relative reduction in insulin resistance (1).


A further study, which looked at weight loss in female patients with obesity, found muscle mass can improve insulin resistance (3).


The results have now created a shift in what many clinicians used to advise their patients, lose weight. While weight loss remains a crucial factor for improving metabolic health such as managing insulin resistance, research is now suggesting fitness and muscle building is another option.

Weight Loss

Studies show that losing weight can help insulin resistance. A study found that losing weight with or without exercise significantly improved insulin resistance. Weight loss does not have to be achieved through low-calorie dieting. Instead, it can be done through simply eating better. Opt for a whole food diet, plant-based foods and minimal animal products.



Magnesium deficiency can lead to diabetes. A high sugar diet depletes your body of magnesium, this is because for sugar to be processed the body requires a lot of it and if you do not add any magnesium back into your body either through magnesium rich food or supplementation, you will become deficient.


A study found that cinnamon and components of cinnamon offer many benefits in relation to factors associated with metabolic syndrome, including insulin sensitivity, glucose, lipids, antioxidants, inflammation, blood pressure, and body weight.



The active component curcumin found in turmeric is believed to be the source which holds all the benefits. A 2013 review of studies suggests that curcumin can decrease the level of glucose in the blood.



Sacks, FM., Carey, VJ.,  Anderson, CAM. (2014). Effects of High vs Low Glycemic Index of Dietary Carbohydrate on Cardiovascular Disease Risk Factors and Insulin Sensitivity. JAMA. 312(23): 2531–2541. Available from:





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