Trends in weight change patterns across life course among US adults, 1988–2018: population-based study

BACKGROUND: To examine trends in weight change patterns from young adulthood through midlife to late adulthood and their sex and racial/ethnic disparities among US adults from 1988 to 2018. METHODS: A total of 48,969 participants from the National Health and Nutrition Examination Survey 1988–1994 and 2001–2018 were included. RESULTS: The age-adjusted prevalence of stable non-obesity between young adulthood and midlife declined significantly from 84.1% (95 CI, 82.9-85.3%) in 1988–1994 to 68.7% (67.1-70.2%) in 2013–2018, and between midlife and late adulthood from 71.2% (69.2-73.1%) to 52.4% (50.5-54.2%). The magnitude of increase in the prevalence of weight gain from young adulthood to midlife (from 10.8% [9.9-11.6%] in 1988–1994 to 21.2% [20-22.3%] in 2013–2018; P < 0.001 for trend) was greater than that from midlife to late adulthood (from 14.1% [12.9-15.3%] to 17.2% [16.2-18.1%]; P = 0.002 for trend). The magnitude of increase in the prevalence of stable obesity from young adulthood to midlife (from 3.9% [3.1-4.8%] in 1988–1994 to 9.2% [8.2-10.3%] in 2013–2018; P < 0.001 for trend) was smaller than that from midlife to late adulthood (from 11.2% [10.1-12.2%] to 24.8% [23.3-26.3%]; P < 0.001 for trend). The declining trends in the prevalence of stable non-obesity and increasing trends in the prevalence of weight gain and stable obesity from young adulthood through midlife to late adulthood were also observed for all sex and race/ethnicity subgroups. The magnitude of decrease in the prevalence of stable non-obesity, and the magnitude of increase in the prevalence of weight gain from young adulthood through midlife to late adulthood were greater in men than in women (all P for interaction < 0.01). Weight gain patterns for those aged ≥ 65 years were substantially different from the younger age groups. CONCLUSIONS: More young people born in later years are encountering obesity and accumulate greater obesity exposure across their lives than young people born in earlier years. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-023-17137-x.