A helpful tool is the glycemic index. It is a measure of how much 100 grams of a given food increases blood glucose in comparison to how much 100 grams of pure glucose affects it. The score ranges from 0-100. The glycemic index gives useful information but has its limitations. For one thing, the glycemic index of a food is based on an average; our personal response may be different. Also, the food we are interested in may come in servings above or below 100 grams. The food may have a low glycemic index, but if our serving size is greater than 100 grams, it may still send our blood sugar soaring. With that in mind, the concept of the glycemic load was developed. That is an estimate of how much a particular serving size of a food will affect blood sugar (on average). It is pretty easy to find the glycemic index of foods. You can just use your favorite search engine to look for the GI of particular brands of food. Once you have the glycemic index a glycemic load calculator can find the GL for you. Here is one: https://www.omnicalculator.com/health/glycemic-load.
You enter the glycemic index of the food in question along with the number of grams of carbohydrates, and it spits out the glycemic load. Anything above 20 is considered high; anything below 10 is considered low. According to the MyFitnessPal app on my phone a 6.1 ounce baked potato has 37 grams of carbs. The glycemic index is 95. When I punch that into the calculator it gives a glycemic load of 35.
We need to keep in mind that just because something has a low glycemic load, that doesn’t mean it’s healthy. Fructose doesn’t affect our blood glucose levels much, so it will have a lowish glycemic load, depending on how much is consumed. That doesn’t make it healthy.
We should also remember that the glycemic index values are based on population averages, and that as individuals our responses to various foods can vary greatly. Also, as individuals our responses can vary based on things like whether we have exercised recently, how much sleep we go the night before, how stressed out we are, and the order in which we eat our food.