Abstract Background The association between low birth weight (LBW) and increased risk of obesity, hypertension and cardiovascular disease later in life is well documented in epidemiological studies. However, clinical follow-up studies of LBW populations have only partly supported this. Aims Evaluate associations between LBW and body fat, blood pressure (BP), lung and endothelial function, and maximal oxygen uptake (VO 2max) in 18 year old young adults. Subjects Thirty-seven subjects born prematurely with birth weight < 1501 g (VLBW group), 47 born at term with low weight (< 10th centile) for gestational age (SGA group) and 63 controls with normal birth weight participated in the study. Outcome measures Anthropometric measurements, BP, endothelial function, lung function and VO 2max were recorded. Results Both LBW groups were shorter, lighter, had smaller head circumference and higher subscapular-to-triceps skinfold-ratio than controls. Systolic and mean arterial BP was higher in the VLBW compared with the control group, whereas there were no differences between the groups in endothelial function. The VLBW group had reduced dynamic lung volumes lower carbon monoxide transfer factor and lower VO 2max compared with controls. In particular young adults born VLBW who were also growth retarded in utero had higher indices of central body fat, higher BP and lower VO 2max. Conclusion We found that very preterm birth, but not growth retardation at term, was associated with higher BP and a less favourable fat distribution. In particular, the young adults born VLBW who were also growth retarded in utero had less favourable outcomes.