Among 5,273 PREDIMED participants aged 60–80 (61% women) at high cardiovascular risk, those accumulating ≥100 MET·min/day of moderate-to-vigorous leisure-time physical activity (MVLTPA) carried BMI values 1.27–1.48 kg/m² lower and waist-to-height ratios 0.021–0.026 smaller than less active peers. Adequate activity linked to a 34% reduced hazard of central adiposity (HR 0.66, 95% CI 0.56–0.77), while a 24% obesity risk reduction was observed in women only. Nonlinear dose-response modelling revealed that benefits plateaued around 400 MET·min/day — roughly 60–90 minutes of brisk walking daily — suggesting diminishing returns beyond that threshold.
This analysis extends the PREDIMED cohort's already substantial legacy into adiposity trajectory research, a domain previously dominated by short-term RCTs measuring simple waist circumference. Using waist-to-height ratio — a more age-sensitive central adiposity marker — adds meaningful granularity. The sex-specific obesity finding (p-interaction = 0.084) is suggestive but falls short of conventional significance, warranting cautious interpretation. Critically, this is an observational study and residual confounding from diet quality, socioeconomic status, or reverse causation cannot be excluded. Activity was self-reported via the Minnesota questionnaire, introducing recall bias. As a preprint not yet peer-reviewed, these findings may shift with formal scrutiny. Still, the dose-ceiling insight is practically useful: clinicians can frame ~400 MET·min/day as a realistic, achievable target for older adults managing cardiovascular and metabolic risk simultaneously.
