New study: Adolescent diets that include potatoes are associated with better diet quality

American youth between two and 19 years-old have the lowest measures of diet quality compared to other age groups;[1] and nutrition thought leaders have called for effective strategies to reverse this trend and improve adherence to dietary recommendations. Now, new research published in Nutrients finds U.S. adolescents who eat potatoes have higher quality diets than those who do not consume potatoes, regardless of how the potatoes are processed or prepared. Compared to no potato consumption, results showed that eating potatoes in any form (baked, boiled, mashed, in mixed dishes and fried) was associated with higher intakes of several essential nutrients, including dietary fiber and potassium – two nutrients of public health concern^[2] – and improved nutrient adequacy.

“The potato is a nutrient-dense vegetable that provides important, critically under-consumed nutrients to adolescent diets,” says Victor Fulgoni, III, PhD and study co-author. “Given their popularity—more than half (56%) of those surveyed reported eating some form of potatoes—there are opportunities to lean into these findings to make it easier for young people to find, cook and enjoy potatoes as part of a healthy dietary pattern.”

Researchers gathered dietary information from 16,633 nine- to 18-year-olds participating in the National Health and Nutrition Examination Survey (NHANES) 2001-20018. This study used Healthy Eating Index-2015 (HEI), a validated measure of diet quality, to determine how closely the participants’ diets adhered to the 2015-2020 Dietary Guidelines for Americans. Although differences in HEI scores between potato consumers and non-consumers were statistically significant, the changes were modest; for many nutrients, intake and adequacy improved with increasing potato consumption. Specifically:

• HEI scores were 4.7% higher among those who consumed potatoes that were baked/boiled, mashed or eaten as part of a mixed dish compared to those who ate no potatoes.
• HEI scores were 2% and 1.6% higher than potato non-consumers, respectively, among adolescents who ate either fried potatoes or those who ate fried potatoes and/or potato chips.

“Our findings show that potatoes play an important role with helping adolescents better meet the recommendations set forth in the Dietary Guidelines for Americans,” notes Fulgoni. “This is an important goal as, according to the USDA Agricultural Research Service, children and adolescents have the lowest HEI scores among any age group in the U.S. – just 53 out of an ideal HEI score of 100.”

“Our results also bring attention to the ‘company potatoes keep,’” Fulgoni adds. “Fried potatoes and potato chips are often paired with less nutrient-dense foods, which can’t be teased out in this type of study but may explain the slightly lower diet quality scores among these groups of potato eaters compared to baked/boiled potato eaters. Additional clinical trials are needed to better elucidate this situation.”

Study Design, Strengths and Limitations

Nutrition intake was determined by using two 24-hour dietary recalls. The first was conducted in person; the second was performed over the phone. Adolescents aged nine to 11 were assisted by parents or guardians, while those aged 12-18 provided recalls on their own. Based on their responses, participants were classified into one of four groups:

• Potato non-consumers
• Consumers of baked, boiled, mashed potatoes and potato mixtures
• Consumers of baked, boiled, mashed potatoes and potato mixtures + fried potatoes
• Consumers of baked, boiled, of baked, boiled, mashed potatoes and potato mixtures + fried potatoes + potato chips

Usual intake of nutrients was determined using the National Cancer Institute method, and diet quality was calculated using HEI-2015 scores after adjusting for demographic factors. The HEI-2015 includes 13 subcomponents, each reflecting an aspect of the 2015-2020 Dietary Guidelines for Americans.

The strengths of the study include its use of a large nationally representative database (NHANES 2001-2018) and the use of multiple covariates to help eliminate potential confounding factors. However, the researchers also acknowledge a few limitations namely, the cross-sectional study design cannot be used to determine causal relationships, and dietary recalls may be subject to inaccurate reporting. Additionally, even with the use of covariates, residual confounding may exist.

The research manuscript, “Intake of potatoes is associated with higher diet quality, and improved nutrient intake and adequacy among US adolescents: NHANES 2001-2018 analysis," is published in Nutrients (https://doi.org/10.3390/nu13082614). Authors include Sanjiv Agarwal, PhD, NutriScience, LLC and Victor L. Fulgoni, III, PhD, Nutrition Impact, LLC. Funding was provided by the Alliance for Potato Research and Education, however APRE had no input on interpretation of the results or in drafting the manuscript.

[1] National Center for Health Statistics, What We Eat in America/National Health and Nutrition Examination Survey, 2015-2016. Healthy Eating Index-2015 Scores—U.S. Department of Agriculture, Center for Nutrition Policy and Promotion, access https://www.fns.usda.gov/resource/healthy-eating-index-hei

[2] U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. 9th Edition. December 2020. Available online: https://DietaryGuidelines.gov