Once a staple in the American diet, the potato fell from grace in recent years when diets like the Atkins, South Beach, and the Zone made "carb" a four-letter word.
These diets considered potatoes equivalent to white bread and sugar. Potatoes, they claimed, have a high "glycemic index" and trigger insulin levels in the blood to spike, causing the body to store fat.
Even though the low-carb craze has died down, the glycemic index theory has gained in popularity. But, what are the facts? Are potatoes health food or junk food? And is the glycemic index a useful tool or just hype?
But after you hear this advice, you may want to dust off your potato mashers and peelers, you may want to give the spud a second chance!
Potatoes are surprisingly nutrient-dense, meaning they offer a lot of nutrients for relatively few calories. At only 100 calories for a medium potato, they're also good for portion control. A medium potato with the skin provides 4.3 g of protein, 3 g of fiber, 45 percent of the daily requirement for vitamin C, and 720 mg of potassium - nearly double the potassium of a medium banana.
And the myth that the potato's nutrition is in the skin is just that - a myth. Removing the skin just loses some fiber. Also, contrary to popular belief, potatoes are complex carbohydrates - unlike sugar and white bread, which are simple carbohydrates.
Complex carbohydrates take longer to digest than simple carbohydrates, leaving you fuller longer. The health benefits of vegetables are well-documented, and potatoes offer a delicious and versatile way to meet the recommended 5-9 daily servings of fruits and vegetables. The U.S. dietary guidelines recommend lots of complex carbohydrates like potatoes and other vegetables.
"Potatoes themselves are a good food, especially with the skin," says Alice Lichtenstein, D.Sc., Gershoff Professor of Nutrition Science and Policy at the Friedman School of Nutrition Science and Policy at Tufts University . "They are fine to be included in a varied diet, but if the primary form is French fries, that's not fine given the obesity epidemic."
So, mash them, boil them, roast them, bake them - just don't fry them!
If the potato is so healthful, how did its reputation become so tarnished? With low-carb diets billed as the "magic bullet" in managing weight, the potato, like other carbohydrates, was left by the wayside. Now, the popular glycemic index is popular, and it, too scorns the humble potato.
The glycemic index ranks carbohydrates: glycemic index (GI) values for foods are calculated by comparing their immediate effect on blood glucose with an equal carbohydrate portion of a reference food, usually glucose.
So, low-GI foods are below 55, medium-GI foods are between 55 and 70, and high-GI foods are over 70. From a nutrition standpoint, the major problem with the glycemic index is that it does not correspond to nutrient density.
For example, potatoes, despite their great nutritional content, have a higher GI index than the less-nutritious ice cream and Coke.
Though most nutritionists, and the American Dietetic Association, are skeptical of the GI theory, some prominent nutritionists support the glycemic index as a tool to prevent chronic disease.
"There are a lot of unanswered questions," says Lichtenstein. "I don't think there is enough adequate data. We're still learning about the glycemic index and how it fits in the dietary guidelines. It's premature to base any dietary decisions on the glycemic index."
While more research needs to be conducted, some studies have shown that individuals who followed a low-GI diet over many years were at a significantly lower risk for developing diabetes, heart disease, and obesity.
For now, it's important that nutrient-dense, complex carbohydrates, like potatoes, form the basis of a healthful diet. Eat a variety of fruits and vegetables, and broaden your horizons - try a blue or sweet potato.
