By: Jenny Heap MS, RDN
Consumer beliefs about carbohydrates tend to be somewhat black and white: For some, there are “good carbs” and “bad carbs.” Others question the value of carbohydrates altogether. The popularity of low-carbohydrate diets has fueled confusion and apprehension about carbohydrate-rich foods. The uncertainty goes beyond added sugars and “empty-calorie” sweets. Even starchy vegetables like potatoes and corn are getting the side eye – and as the vegetable most commonly consumed in the United States, potatoes have taken center stage.
As nutrition professionals, we know that the story behind sugars, starches, and dietary fibers is remarkably nuanced. We understand the tendency to simplify and categorize foods as “good for you” or “off limits” is far from intellectual laziness. It’s a survival skill; a mental shortcut that we’ve honed as humans to grease the wheels on daily decision making. When it comes to choosing carbohydrates, there is ample reason to question our assumptions.
In a 2023 nationwide survey administered by Potatoes USA, most consumers ranked dark green vegetables as the healthiest, and starchy vegetables as the least healthy of the vegetable categories. Among 10 commonly consumed vegetables (onions; leafy greens; tomatoes; black, pinto, and white beans; broccoli, green beans; corn; sweet potatoes; and white potatoes), white potatoes were ranked lowest in perceived healthfulness and were joined by sweet potatoes and corn in the bottom four, suggesting ongoing misperceptions about the nutritional value of potatoes and a prioritized focus on carbohydrate content. [1]
These consumer perceptions aren’t surprising; they’re often reflected by credible sources. Epidemiological studies often categorize potatoes with sugar, sweets, and empty-calorie refined carbohydrate foods in examining disease risk.[2] Another example is the glycemic index (GI), a research-backed food scoring system that attempts to predict the impact of individual foods on changes in blood glucose. The GI score of a boiled potato is high, landing potatoes in the same category as doughnuts and jellybeans. While GI scores appear to simplify food choices, the practical application is limited. Changes in blood glucose from eating potatoes (and other foods) vary significantly and ultimately depend on several factors, including the method of preparation, the macronutrient composition of other foods consumed at or near the same time, and (more specifically for potatoes) the maturation, variety, and origin. The glycemic response to any given food can also vary widely between individuals.[3] [4] [5] Selecting foods based solely on GI score discounts real-life variables that significantly impact the glycemic response when foods are consumed outside of a controlled laboratory setting.
Attempts to simplify our understanding of carbohydrates blur important nutritional and functional differences between carbohydrate-rich grains, vegetables, and legumes and between the whole and refined versions of each. Like individual amino acids and fatty acids, carbohydrates can have vastly different functions and contribute to health in different ways.
Where do potatoes fit in?
Starch is the primary carbohydrate supplied by potatoes. It is present in two forms: amylopectin and amylose, in a 3:1 ratio. While amylopectin is easily broken down into single-sugar units for energy use or storage, amylose (a resistant starch) is not broken down by digestive enzymes. It functions somewhat like a soluble fiber, undergoing fermentation by gut microbes and producing beneficial short-chain fatty acids, or SCFAs. Though the cooking process makes amylose more digestible, cooling potatoes after cooking returns some of the starch to its resistant state. Potatoes also provide dietary fiber, primarily composed of cellulose, an insoluble fiber that helps promote satiety and bowel regularity.
In evaluating carbohydrates, it’s important to think in terms of how they are packaged and what nutrients come with them. Potatoes are an important (and convenient) vegetable source of the following nutrients. One medium skin-on potato supplies:
- Carbohydrates: 26g carbohydrates.
Glucose is the fuel preferred by the red blood cells and the brain and central nervous system. In fact, the Estimated Average Requirement for carbohydrates – 130 grams of carbohydrates per day – was calculated based on the brain’s glucose requirements alone. A higher intake is recommended to support physical activity.
Potatoes are a practical source of energy and nutrients. Carbohydrates are the main source of energy for muscles, which store carbohydrates as glycogen for quick access during physical activity. Eating easily digestible carbohydrates before physical activity help fuel performance and are necessary post-exercise, to replenish glycogen stores and help delay muscle fatigue during subsequent workouts.
- Fiber: 2g of fiber, 7% of the Daily Value.
Fiber in potatoes, composed mostly of cellulose, enhances satiety, contributes to bowel regularity and may have beneficial effects on the gut microbiome.
- High-Quality Protein: 3g of high-quality plant protein.
It’s the biological value (BV) of potato protein that might surprise you. Depending on the variety, the BV comes in anywhere between 90 and 100 –approaching that of an egg – and is higher in biological value than protein from soybeans and legumes. [6] Potatoes, while not high in protein, offer more per serving than most other foods commonly consumed from the vegetables and legumes category.
- Vitamin C: 20mg of vitamin C, 30% of the Daily V
Vitamin C is essential for the synthesis of collagen, which provides structure and elasticity to connective tissues throughout the body. It also supports wound healing and immune function. Another important benefit of vitamin C is that it improves the bioavailability of iron found in plant foods.
- Iron: 1mg of iron, 6% of the Daily Value.
Potatoes’ impressive vitamin C content and very low (or nonexistent) antinutrient levels make the bioavailability of iron shine compared to that of other plant foods rich in iron.[7]
- Vitamin B6: 2mg of vitamin B6, 10% of the Daily Value.
Vitamin B6 plays an important role in immune function, protein and carbohydrate metabolism, and in early cognitive development through the formation of neurotransmitters.
- Magnesium:7mg magnesium, or 11% of the Daily Value
Magnesium helps regulate blood pressure and blood glucose levels, along with muscle and nerve function. Research suggests that 5% of the magnesium in Americans’ diets comes from potatoes. [8]
- Phytonutrients: Potatoes are rich in antioxidants. Beyond vitamin C, they offer polyphenols, anthocyanins, and flavanols in varying amounts depending on the variety. Many varieties are grown locally in Wisconsin, including red, blue and purple, white, yellow-gold, Russet and Fingerling.
What is the significance of correcting misperceptions?
Cultural relevance:
The Dietary Guidelines for Americans recommend potatoes as part of the starchy vegetable category. Alongside staples like corn, cassava, yams, and taro, they provide sustained energy and vital nutrients across various cultures. In a recent survey, potatoes still play a significant role within family and cultural food traditions, with more than half of Hispanic, (54%), Black (52%), white (54%), and Native American (50%) respondents confirming that potatoes are foundational to their family and cultural food traditions.[9]
Affordability and Accessibility:
Misinformation is a barrier that can disproportionately impact those who stand to benefit most. Potatoes are a familiar and affordable staple across many cultures in the US. In fact, they are among the vegetables with the highest nutrient score per dollar, sitting at the top with carrots and sweet potatoes. (Nutrient scores were based on the Nutrient Rich Foods index and nine nutrients to encourage: protein; fiber; vitamins A, C, and E; calcium; iron; magnesium; and potassium; and on three nutrients to limit: saturated fat, added sugar, and sodium.)[10] You can buy more potatoes per dollar compared to other vegetables, making them not only nutritious but also cost-effective. Potatoes provide a significant source of nutrition, especially for populations at risk for nutrient deficiencies, so it’s critical for health professionals to address misconceptions that might serve as barriers to access.
Declining vegetable intake:
It’s not news that Americans are falling short of vegetable intake recommendations. In fact, the Produce for Better Health (PBH) Foundation’s 2021 State of the Plate research indicated that produce consumption in general had declined in the US by 10% since 2004, and that Americans were reaching for produce just once a day – or less! According to the Dietary Guidelines for Americans, only one in 10 Americans is meeting vegetable intake recommendations and all age groups are coming up short in every vegetable category – including starchy vegetables. This decline underscores the importance of correcting misperceptions wherever they exist across the produce category.
Sustainability:
According to a 2008 statement from the Food and Agriculture Organization of the United Nations: “The potato produces more nutritious food more quickly, on less land, and in harsher climates than any other major crop – up to 85 percent of the plant is edible human food, compared to around 50 percent in cereals.” [11] Unintended consequences of misinformation/misperceptions could keep consumers from supporting a local, sustainable crop.
Wisconsin-grown potatoes offer more than just great taste. Local and sustainably sourced, they’re packed with nutrition no matter the variety. Potatoes’ energizing and satisfying carbohydrates are far from a nutritional compromise. With high-quality protein, potassium, vitamin C, and beneficial phytonutrients, they come in a nutrient-rich package worthy of center plate. To learn more about potato nutrition and Wisconsin grown potatoes visit eatwisconsinpotatoes.com.
[1] Meeting Street Insights conducted an online nationwide survey among 1,000 adults (aged 18+) between December 15-18, 2023. Respondents were sourced from Dynata’s online general population consumer panel. Standard demographic quotas were set to mirror Census data for region, gender, age, and race; weights were also applied so that education level aligned with Census figures. The credibility interval for a sample of N=1,000 is +/-3.53%. Potatoes USA commissioned the study.
[2] Drewnowski A, Maillot M, Vieux F. Multiple Metrics of Carbohydrate Quality Place Starchy Vegetables Alongside Non-starchy Vegetables, Legumes, and Whole Fruit. Front Nutr. 2022;9:867378. Published 2022 May 2. doi:10.3389/fnut.2022.867378
[3] Fernandes G, Velangi A, Wolever TMS. Glycemic index of potatoes commonly consumed in North America. J Am Diet Assoc. 2005;105:557-562.
[4] Henry CJ, Lightowler HJ, Strik CM, Storey M. Glycaemic index values for commercially available potatoes in Great Britain. Br J Nutr. 2005 Dec;94(6):917-21.
[5] Mattan NR, Ausman LM, Meng H, et al. Estimating the reliability of glycemic index values and potential sources of methodological and biological variability. Am J Clin Nutr. 2016;104:1004-1013.
[6] King JC, Slavin JL. White potatoes, human health, and dietary guidance. Adv Nutr. 2013;4(3):393S-401S. Published 2013 May 1. doi:10.3945/an.112.003525
[7] Beals, K.A. Potatoes, Nutrition and Health. Am J Potato Res. 2019;96:102–110. https://doi.org/10.1007/s12230-018-09705-4
[8] Beals, K.A. Potatoes, Nutrition and Health. Am J Potato Res. 2019;96:102–110. https://doi.org/10.1007/s12230-018-09705-4
[9] Meeting Street Insights conducted an online nationwide survey among 1,000 adults (aged 18+) between December 15-18, 2023. Respondents were sourced from Dynata’s online general population consumer panel. Standard demographic quotas were set to mirror Census data for region, gender, age, and race; weights were also applied so that education level aligned with Census figures. The credibility interval for a sample of N=1,000 is +/-3.53%. Potatoes USA commissioned the study.
[10] Drewnowski A. New metrics of affordable nutrition: which vegetables provide most nutrients for least cost? J Acad Nutr Diet. 2013;113(9):1182-1187. doi:10.1016/j.jand.2013.03.015
[11] Mackay, G R. New Light on a Hidden Treasure. (Rome: FAO), 2009;376–376. doi: 10.1017/s0014479709007686
