The trend: Obesity rates among US adults are declining after years of increases.

• Newly released CDC data shows adult obesity at 40.3% for its 2021 to 2023 survey period, down from 42.4% from the previous 2017 to 2018 survey, marking the first downturn in more than a decade.
• Note: The CDC is the gold standard health data source, but its report publishing often lags.
• Gallup’s annual tracking showed a similar continuing decline for 2025, with 37% of US adults reporting obesity, down from 39.3% in 2023.

The caveat: While adult obesity declined, obesity rates climbed to 21.1% for children and teens ages 2-19 in 2023, up from 19.3% in 2017 to 2018.

Why it matters: Declining US adult obesity rates coincide with the rapid uptake of GLP-1 weight loss drugs.

• The CDC data may include early effects of weight loss drug use with Novo Nordisk’s GLP-1 Wegovy approved in 2021. (Note: Eli Lilly’s Zepbound wasn’t approved until late 2023.)
• Gallup data shows a jump in GLP-1 use specifically for weight loss with 12.4% of adults taking them last year, up from 5.8% in February 2024.
• Gallup noted that the 40–64 age group leads the decline in obesity, and represent the highest current users—and the fastest-growing market—for GLP-1 weight-loss drugs since Q1 2024.16.2% of 40-49-year-olds and 17% of 50-64-year-olds reported taking them in October 2025.

Implications for pharma marketers: The adult obesity rate decline suggests that GLP-1s are contributing to meaningful population-level effects, but the gains are uneven. Older adults are seeing greater weight loss, while teen obesity rates continue to rise, underscoring demographic gaps.

As social media amplifies narratives of quick and easy weight loss, drugmakers need to shape expectations. Positioning GLP-1s as one part of comprehensive weight management, alongside healthy lifestyles, physical activity, and responsible use are key to sustaining progress and reinforcing long-term outcomes.

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