Carbohydrates in potatoes are mainly starch - a substance that is digested and metabolized to glucose relatively quickly in the small intestine.
The glycemic index (GI) is a standard measure reflecting the rate at which food increases blood sugar after eating: the higher it is, the faster blood sugar increases.
According to nutritional analysis, potatoes in their original form often fall into the group of foods with high GI, meaning that they are quickly digested by the body and lead to rapidly increasing blood sugar after meals, even equivalent to sugary drinks if processed in grilled or ground form.
For example, baked potatoes have a GI of up to about 111, while boiled potatoes are about 82, both are high levels compared to many other fiber-rich vegetables.
Many large-scale epidemiological studies have examined the link between potato consumption and the risk of type 2 diabetes.
A compilation of data from 7 major pre-medical studies in the US (over 105,000 people) published in 2024 showed a complex link between total potato intake and the risk of diabetes;
However, the consumption of french fries is closely related to the increased risk of diabetes due to high starch content combined with bad fats.
Moreover, public health experts emphasize that high GI and refined carbohydrate content in potatoes are the reasons why it can "cause blood sugar shock" - especially when potatoes are consumed in meals lacking fiber and protein to slow down glucose absorption.
Not only the root type, but the way potatoes are processed determines the rate of blood sugar increase after eating.
French fries not only have high GI but also contain a lot of unhealthy fats and calories - this not only affects blood sugar but also increases the risk of insulin resistance, overweight and metabolic syndrome.
Conversely, simple steamed, boiled or grilled potatoes (without added fat) can cause less severe blood sugar spikes than fried versions, because nutrients such as fiber are more intact and do not contain added excess fat.
