by Nicole Holovach, MS, RD, LDN
Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women. Typical symptoms include hirsutism, menstrual irregularity, and infertility. Furthermore, PCOS predisposes women to metabolic dysfunction, overweight and obesity, and an increased risk of type 2 diabetes. Obesity exacerbates the insulin resistance that is a feature of PCOS in many women. Reducing insulin levels and improving insulin sensitivity are an essential part of treatment and management.
Diet plays a significant role in the regulation of blood sugar and insulin levels. Low-glycemic index diets are currently popular with both registered dietitians and patients in the management of PCOS.
The glycemic index is a rating of how much a food is going to potentially raise your blood sugar levels. Glycemic load in another rating that was basically created to address one of the shortcomings of glycemic index, which is it doesn’t take serving size into account. So watermelon is high on the glycemic index, but the amount of carbohydrates in a general serving size of watermelon is pretty low.
I have a confession to make: I’ve never loved the glycemic index. Even in my initial days of nutrition counseling years ago when it was first getting popular, it seemed rather arbitrary. Of course whole foods like vegetables, fruits, and legumes would be better for a person’s blood sugar control than refined and processed foods like bagels, crackers, cookies, cakes, doughnuts, croissants, waffles, and most packaged breakfast cereals! And I still resent the fact that the glycemic index has just about destroyed the reputation of healthy, nutrient-dense foods like carrots, watermelon, bananas, and white potatoes.
But, my biggest *issue* with the glycemic index is that the glycemic index of a particular food can be influenced by what it is eaten with. Food is rarely eaten in isolation, rather as part of a meal. A white potato, combined with protein and fat, has a much lower effect on your blood sugar than a potato alone. Who eats a potato by itself? Foods like bananas that you might grab and go, can be made even healthier by combining with fat or protein, like almond butter or yogurt. Also, the way a food is cooked affects its rating on the glycemic index. Al dente pasta has a lower rating on the glycemic index than pasta that is cooked longer.
Although the research is generally not supportive of either glycemic index or glycemic load for weight loss, insulin, or blood sugar control, it continues to be popular in forums and among health professionals in the management of PCOS. Instead of having patients memorize a list of random foods, I’d much rather focus on having them plan regular meals and snacks with a healthy balance of carbohydrates, protein, and fat for blood sugar control. And also focus on the myriad of other things that can improve insulin sensitivity like sleep, stress, and physical activity.