To investigate the relationship between the dietary approaches to stop hypertension (DASH)-style dietary patterns in childhood and cardiometabolic risk (CMR) in adolescence/early adulthood.

Data were obtained from the Avon Longitudinal Study of Parents and Children (ALSPAC) prospective cohort. Diet diary data collected at 7, 10 and 13 years were used to calculate DASH-style diet scores (DDS). Multivariable linear regression models were used to investigate the associations between the DDS at 7, 10 and 13 years and CMR scores, calculated at 17 and 24 years.

The ALSPAC cohort included children born in south-west England in 1991–1992.

Children with complete dietary, covariate and cardiometabolic data at 17 (n 1,526) and 24 years (n 1,524).

A higher DDS at 7 and 10 years was negatively associated with CMR scores at 17 years (β = –0·64 (95 % CI –1·27, –0·006), Ptrend=0·027 for fifth v. first DDS quintile at 7 years; β = –0·73 (95 % CI –1·35, –0·12) and Ptrend=0·037 for fifth v. first DDS quintile at 10 years) and at 24 years (β = –0·92 (95 % CI –1·49, –0·34) Ptrend = 0·001 for fifth v. first DDS quintile at 7 years; β = –0·60 (95 % CI –1·20, –0·05) Ptrend = 0·092 for fifth v. first DDS quintile at 10 years). No associations were found between the DDS at 13 years and CMR score at 17 and 24 years.

Greater adherence with a DASH-style diet during childhood was associated with better cardiometabolic health in adolescence/adulthood in the ALSPAC cohort. The components of the DASH diet could be recommended to improve children’s cardiometabolic health.