Nearly half of Americans
are obese. With rates of obesity more than doubling between 1990 and 2021, obesity is a significant risk factor for chronic diseases, including heart, liver, and kidney disease, high blood pressure, diabetes, some cancers, and dementia. Increased body mass index corresponds to a higher risk of premature death. Addressing the rising rates of obesity is of great importance in the prevention and control of chronic disease.
The type of food we consume plays a key role in obesity. Studies suggest that the consumption of highly processed food increases obesity -- when we eat processed food, we feel less full and eat more calories. As of 2018, ultra-processed foods made up two-thirds of the food consumed by children and more than half of the food consumed by adults.
But the type of food people eat is not the only cause of obesity. The rise in ultra-processed food consumption beginning around the early 2000s was preceded by substantial declines in physical activity. In 1991, 42% of high school students attended daily physical education classes; as of 2023, just 27% did. The 2024 U.S. Report Card on Physical Activity for Children and Youth found that fewer than one in three children ages 6-17 years met the goal of 60 minutes of daily physical activity. In another study, physical activity in youth decreased by about 4%-to-5% per year of age.
These trends were highlighted in the recent Make American Healthy Again (MAHA) report, but writing about it isn't enough. From regulating artificial food dyes to banning junk food from the SNAP program in some states, the Trump administration is clearly taking aim at nutrition. To effectively address chronic disease, efforts to promote exercise must not fall by the wayside.
Evidence suggests diet-plus-exercise programs are superior to diet alone in producing weight loss long-term. Additional research shows that regular physical activity in schools lowers the rates of obesity. One study found that increasing school physical education from 1.5 hours per week to 4.5 hours per week in kids ages 5‐11 years (at inclusion) resulted in an approximately 50% reduction in obesity risk after 5 years. Other studies have found that short (45-minute), regular, high-intensity activities in school can lead to improved health outcomes.
Yet, the amount of physical education provided in schools varies. Federal guidelines state that school-age youth should do 60 minutes or more of physical activity daily. The Society of Health and Physical Educators (SHAPE) guidelines suggest a minimum of 2.5 hours per week of physical activity in elementary school and nearly 4 hours per week for middle and high school kids. State legislation mandating minimum physical activity in schools is strongly predictive of schools including structured physical education curricula. While nearly 75% of states require physical education in elementary through high school, over half of states permit students to substitute other activities, or otherwise fail to mandate a specific amount of instructional time.
It's time to double down on physical education in schools. Federal leaders should encourage states to ensure that minimum physical activity standards meet current guidelines for each age group. Institutional accountability can be incentivized through grant programs and other awards. Similarly, student-level engagement can be incentivized based on specific fitness goals.
The decline in physical activity also mirrors the rise of the media-entertainment complex, which is ripe for intervention. In 2024, U.S. revenue tied to the digital media market was estimated at nearly $300 billion and is projected to rise to over $560 billion in the next 5 years. Almost two in three children sit and watch television or play video games for more than 2 hours per day, while computer use outside of school has also increased. Also of note, watching more than 2 hours of television per day has been associated with increased risk for attempted suicide among adolescents. Given how ubiquitous the use of televisions, smartphones, and computers has become, we need to establish maximum standards for daily screen use.
We also need programs to encourage adults to be more physically active. More partnerships between professional sports organizations and local communities are needed to support access to playing fields, courts, and supervised competitions. Financial incentives among workers in Japan led to significant increases in daily step counts. Organizations in Europe have attempted to increase physical activity in the workplace by making exercise into a game and offering prizes for various accomplishments. Tax relief could be offered to employers who offer gym memberships, allocate time for exercise, or provide additional paid time off for employees who meet fitness goals.
Novel therapies like glucagon-like peptide-1 medications that lead to weight loss and reduce heart disease are not a magic bullet. And neither are technologies like glucose-monitoring devices or wearable fitness apps that are unlikely to reach scale or the populations that need them most. Furthermore, some research has suggested there are potential harms associated with the use of diet- and fitness-monitoring apps. What is needed are evidence-based, structural, community-level interventions that support ongoing exercise. These reach beyond obesity alone, and can have benefits for mental health and socialization too.
To address the chronic disease epidemic, we must establish a culture of physical activity beginning in childhood that continues throughout life. To do so will require leadership and federal support for new legislation and incentives. It is time for Americans to move.
Lao-Tzu Allan-Blitz, MD, MPH, is a pediatrician and adult medicine specialist at Brigham and Women's Hospital and Harvard Medical School in Boston. Jeffrey D. Klausner, MD, MPH, is a professor of population and public health sciences at the University of Southern California Keck School of Medicine in Los Angeles, and a former CDC medical officer.
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.