The UCL-led review of over 50 studies from UK birth cohorts since 1946 reveals a clear 'generational health drift,' with obesity and mental health issues emerging earlier in life for post-Baby Boomer groups. This observational synthesis, drawing on tens of thousands of participants across datasets like the 1958 and 1970 British Birth Cohorts, avoids reliance on diagnostic artifacts by using objective biomarkers and validated self-reports. However, the original coverage underplays how this reverses prior life expectancy gains amid austerity-driven cuts to preventive services since 2010, a factor not fully isolated in the cohort comparisons. Related peer-reviewed work in The Lancet Public Health (2023, n=~20,000 adults) links similar UK trends to rising multimorbidity from processed food environments and economic precarity, while ONS healthy life expectancy data (2024 release) shows stalled gains post-2010s, confirming midlife worsening as cohort-driven rather than aging alone. No RCTs exist here due to generational scope, but the large-scale longitudinal design strengthens causal inferences on preventable exposures like inequality over genetic limits. Policy fallout includes ballooning NHS costs by 2050 as more years are spent in poor health, demanding urgent shifts from treatment to upstream interventions on diet, mental health access, and housing.