Diet and Physical Activity Among U.S. High School Students, 2019

Nutrition and physical activity matter for growth, development and preventing chronic disease. About half of U.S. adults have a chronic disease linked to poor diet quality and too little activity, such as type 2 diabetes, cardiovascular disease or obesity, and eating and activity habits formed in childhood tend to carry into adulthood.

Federal guidelines set the targets. The Dietary Guidelines for Americans 2015–2020 call for a variety of vegetables, fruits and whole grains, and for limiting sodium, added sugars and saturated and trans fats. The Physical Activity Guidelines for Americans, 2nd edition, call for children and adolescents aged 6–17 to get at least 60 minutes of moderate-to-vigorous activity every day, mostly aerobic, with muscle- and bone-strengthening activity on at least 3 days a week each.

Earlier data showed most adolescents falling short, with differences by sex and race and ethnicity. CDC used the 2019 Youth Risk Behavior Survey (YRBS) — a school-based survey of a nationally representative sample of public and private high school students, grades 9–12, run every two years since 1991 — to update the picture and trace trends back to 2009. The results appeared in an MMWR supplement.

Eating and drinking in 2019

During the 7 days before the survey:

More male than female students drank soda daily (18.2% versus 11.7%) and sports drinks daily (14.0% versus 7.1%). Black students were more likely than White or Hispanic students to eat fruit less than once a day (47.8% versus 42.1% and 39.5%), to drink a sports drink daily (15.6% versus 9.3% and 11.9%) and to drink fewer than 3 glasses of water (54.8% versus 44.2% and 44.2%); 54.8% of Black students ate vegetables less than once a day. More Hispanic than White students ate vegetables less than once a day and drank sports drinks daily, and more Black than White students skipped breakfast on at least one day (21.1% versus 15.3%).

Trends in eating

• Fruit and vegetables: the share eating them less than once a day rose from 2009 to 2019. Among Black students both measures held steady from 2009 to 2015 and then rose.
• Breakfast: the share not eating breakfast every day rose from 2011 to 2019, and again from 2017 to 2019.
• Soda: the share drinking it daily fell from 29.2% in 2009 to 15.1% in 2019, among both sexes and White, Black and Hispanic students. Overall and among female students it held steady from 2009 to 2013 and then fell.
• Sports drinks: daily use fell from 13.8% in 2015 to 10.6% in 2019.
• Water: the share drinking fewer than 3 glasses a day fell from 50.5% in 2015 to 44.6% in 2019.

Students who drank sugar-sweetened soda or pop at least once a day, 2009–2019. CDC figure.

Students who drank a sports drink at least once a day, 2015–2019. CDC figure.

Physical activity in 2019

White students were more likely than Black students to be active every day (25.6% versus 21.1%), to meet both guidelines (18.4% versus 13.4%) and to play on a team (62.0% versus 56.1%), and more likely than Hispanic students to be active every day (25.6% versus 20.9%) and to play on a team (62.0% versus 51.6%).

Physical activity and physical education among high school students, overall and by sex, 2019. CDC figure.

Trends. From 2011 to 2019 the share active every day, the share doing muscle-strengthening exercise at least 3 days a week, and the share meeting both guidelines all declined. Daily physical education and team sports showed no significant change from 2009 to 2019, except for a decline in daily physical education among female students.

What the authors concluded

Apart from less soda, fewer sports drinks and more water, students' eating and activity had not improved in a decade and in some ways had worsened. That is a concern, the authors wrote, because these habits affect growth, school performance and chronic diseases including type 2 diabetes, heart disease, hypertension and obesity. About one in five adolescents has prediabetes, and obesity among youths aged 12–19 rose from about 18.1% in 2007–2008 to 20.6% in 2015–2016. Black and Hispanic students had poorer eating and activity patterns than White students, and male students ate less healthily but were more active than female students.

Food. Four in ten students ate fruit less than once a day, and four in ten ate vegetables less than once a day. Girls aged 14–18 need 1.5 cups of fruit and 2.5 cups of vegetables a day, and boys 2 cups and 3 cups. The survey measures how often, not how much, but young people who meet the recommendations usually eat fruit and vegetables several times a day, so less than once a day is likely not enough. Schools can offer several fruit and vegetable choices daily through their meal programs, such as grab-and-go salads.

Drinks. Sugar-sweetened beverages are the main source of added sugars in U.S. youths' diets and are linked to obesity, type 2 diabetes, heart disease and tooth decay; drinking enough water is linked to better diet-quality scores. Despite the declines, these drinks remained common, and intake was higher among boys and among Black and Hispanic adolescents — possibly because beverage companies market them disproportionately to Black and Hispanic youths. The Smart Snacks in School standards, in effect from the 2014–15 school year, cut students' access to sugary drinks at school; health education and community campaigns might reduce it further and steer teens toward water.

Activity. Students fell short of the Healthy People 2020 targets: at least 31.6% meeting the aerobic guideline, 61.2% the muscle-strengthening guideline, 24.1% both, and 36.6% taking daily physical education. With only 25.9% in daily physical education in 2019, the last target was unlikely to be met in 2020. Physical education can supply about 40% of a student's daily activity, yet in 2015–2016, although most states required high schools to offer it, few set a time requirement and many allowed substitutes. Only 57.4% played sports, despite the physical, psychological and academic benefits highlighted by the 2019 National Youth Sports Strategy. The gap between boys and girls might reflect gender stereotypes, self-efficacy, self-consciousness or social influences.

What can help

• Schools can make sure food and drinks sold during the day meet the Smart Snacks standards, serve meals students enjoy, provide free drinking water, offer activity before, during and after school through a comprehensive school physical activity program, and teach health education, coordinated through the Whole School, Whole Community, Whole Child model.
• Parents and community members can reinforce school messages, join school wellness teams, be active with adolescents, support them in moving more and sitting less, and make choices that support healthy eating.
• Community programs that change policies and environments — through information, incentives and better access to healthy options — can improve youths' eating, activity and weight, especially when they combine several strategies and include schools.

One limitation: questions on foods such as fruit ask about frequency, not portion size, so they cannot show whether students meet the amounts recommended for their age and sex.

Sources

• Merlo CL, Jones SE, Michael SL, et al. "Dietary and Physical Activity Behaviors Among High School Students — Youth Risk Behavior Survey, United States, 2019." MMWR Supplements 2020;69(1).
• The report gives two different figures for White students eating vegetables less than once a day (35.5% and 35.3%), and names different sex groups for the decline in sports drinks in its results and its discussion; neither detail is given here. Its visual abstract is not reproduced.