I figured it would be wrong to write a post about potatoes without including the above song. 😉
If they could be their own food group, my husband would be in heaven. Who am I kidding? I would probably be on board with that, too. White potatoes get such a bad rap. But in reality, potatoes are a starch just like anything else that you may pair with your protein and veggies at dinner.
So what are the arguments out there about why sweet potatoes are “better” than white potatoes?
“High Glycemic Index / Glycemic Load”
Glycemic Index (GI) — a number (0-100) based on the impact the food (in a portion containing 50 grams of carbs) has on our blood glucose (or sugar) levels
Glycemic Load (GL) — similar to GI , however, it takes the normal portion you would typically be eating into account
Glycemic Load = (# of available carbs in the portion x Glycemic Index) / 100
For example, carrots have a high GI, but that is based off a serving that has 50 grams of carbohydrates. You know how many carrots that is?
700 grams. Or 5 cups of sliced carrots.
Not many people eat 5 cups of carrots at once, but if that’s you, you’ll probably start turning orange soon. 😉
Other factors such as preparation (boiled, roasted, etc.), added fat, peeled, etc. all affect the Glycemic Index/Load.
Eating carbohydrates with added fat and/or along with a protein, helps prevent such a quick spike in blood sugars. Very rarely do any of us eat only white potatoes with nothing else!
Sources for the GI & GL values also contradict themselves depending on who performed the research.
For example, for sweet potatoes:
- Sweet potato, peeled, baked 45 minutes = 94 GI, 42 GL
- Sweet potato, peeled, cubed, boiled = 46 GI, 15 GL
And for white potatoes:
- Potato, peeled, boiled = 85 GI, 26 GL
- Russet potatoes, baked without fat = 94 GI, 28 GL
- Ontario potato, white, baked in skin = 60 GI, 18 GL
- California white potatoes, cubed, roasted in soybean oil = 72 GI, 14 GL
All this to say, don’t put too much stock in the GI/GL debate on foods. It’s just not practical or reliable.
“Turns into sugar”
Sugar has been the latest thing to be demonized in our society, but there’s so much confusion around it. People are saying “sugar,” but they typically mean white sugar or “sucrose” that you use in baking.
In the nutrition world, “sugar” is another name for carbohydrates. “Simple sugars” include glucose, fructose, & galactose — the smallest units of carbohydrate. Put two of those simple sugars (monosaccharides) together to get a disaccharide.
Glucose + Fructose = Sucrose.
Our body needs “sugars,” especially glucose, to create energy in the form of ATP. That’s what fuels our cells. The type of carbohydrate (e.g. how long the chain of simple sugars is), determines the exact path it goes through in our body. But in simple terms — it will still eventually become a form of “sugar.”
So yes, potatoes of any kind will turn into sugar in our body. But that’s that point — that’s what we want and need to happen!
Upon first glance, sweet potatoes & white potatoes are almost identical in macronutrient composition (e.g. carbohydrates, protein, fat).
Ironically (related to the point above), sweet potatoes have more “sugar” than white potatoes. This is just referring to those carbohydrates that are shorter in chain length. But this makes sense, too, because we all know sweet potatoes do indeed taste sweeter than white potatoes.
As far as micronutrients go, sweet potatoes have white potatoes beat by small margins in many categories, including fiber. That part is true.
To check it out for yourself you can see the entire nutritional breakdown by searching the USDA’s database.
One major difference is that sweet potatoes have a lot of vitamin A whereas white potatoes have almost none. Vitamin A is also found in carrots, romaine lettuce, spinach, cantaloupe, etc. [Worth noting that Vitamin A deficiency is pretty rare in developed countries.]
White potatoes, however, have more folate than sweet potatoes. We also find it in broccoli, asparagus, beans, lentils, strawberries, spinach, etc.
Folate (or folic acid) helps prevent neural tube defects in infants. It’s so important that we add folic acid to many products such as breads and cereals to ensure women are getting enough.
Despite the craze about “superfoods,” no one food is going to provide you all the nutrients you need. That’s why variety is so important. Both sweet potatoes and white potatoes can certainly fit into a balanced diet.